Alternative Learning System

Wednesday, October 13, 2021

Lesson 7 - Six Trigonometric Functions: Introduction to Trigonometry in Taglish

 LESSON 7 – The Six Trigonometric Functions

Pagtutuunan natin sa araling ito ang tungkol sa anim (6) na Trigonometric Functions. Bago natin tukuyin ang mga katangian ng mga ito, balik-aralan muna natin ang mga bahagi ng right triangle kung saan nakabase ang anim na functions ng Trigonometry.




Sinasabing right triangle ang isang trianggulo o tatsulok kung ito ay may isang right angle. Ang right angle ay may sukat na 90 degrees (90o) o π/2 radian o 1.5708 radians ( 90 x π/180; where π≈ 3.1416).



Pagmasdan ang right triangle sa itaas:

Mayroong  espesyal na pangalan para sa bawat gilid o side ng isang right triangle. Ang dalawang gilid ng ΔXYZ (triangle XYZ)  na bumubuo ng right angle, XZ at YZ, ay tinatawag na mga binti  o legs ng tatsulok. Ang pangatlong gilid, XY, ay tinawag na hypotenuse. Ang hypotenuse ay ang gilid sa tapat ng right angle. Ito ang pinakamahabang gilid/side ng right triangle.

Sukatin natin ang haba ng mga gilid ng right triangle:

XY = 25 units YZ = 7 units XZ = 24 units

Ang tatsulok sa itaas ay may 2 acute angles. Alalahanin na acute angle ang tawag sa anggulo o salikop na may sukat na mas malaki sa zero degree ngunit mas mababa sa 90 degrees.

Ang mga acute angles na ito ay ang∠X (angle X) at ∠Y (angle Y).  Ang bawat isa sa mga ito ay naporma sa pamamagitan ng hypotenuse at isang leg o gilid. Ang ∠X ay produkto ng side XY at side XZ, samantalang ang ∠Y ay gawa ng side XY at side YZ.

Ang leg na kasama ng hypotenuse upang makagawa ng acute angle ay tinatawag na adjacent side/leg.

Sa ating halimbawang drawing sa itaas,  ang  leg/side adjacent sa ∠X ay side XZ (o XZ lamang). Ang leg naman adjacent sa ∠Y ay YZ. Dalawa ang side adjacent sa ∠Z; ito ay XZ at YZ.

Opposite side naman ang tawag sa gilid/side/leg na katapat ng angle na pinagbabatayan. Narito ang opposite side ng ating tatlong angle:
∠X ==> YZ ∠Y ==> XZ ∠Z ==>XY

Dapat tandaan na ang opposite side ng right angle (90 degrees) o ∠Z ay ang hypotenuse. Depende sa anggulo o salikop na pinagbabatayan, ang opposite side ng isang acute angle ay maaaring adjacent side naman ng isa pang acute angle at kabaliktaran o vice versa.

Halimbawa, ang opposite side ng ∠X ay YZ, samantalang ang YZ ay siyang adjacent side ng ∠Y; ang XZ ay ang opposite side ng ∠Y, samantalang  ang XZ ay siyang adjacent side ng ∠X .

PAGSASANAY A

Batay sa drawing sa ibaba, sagutin ang mga tanong:



hypotenuse =
side adjacent to ∠A =
side opposite ∠A =
side adjacent to ∠B =
side opposite ∠B =
side opposite ∠C =
side/s adjacent to ∠C =

2. Batay sa drawing sa ibaba, sagutin ang haba ng mga gilid/side:



hypotenuse =
side/s adjacent to ∠A =
side opposite ∠A =
side adjacent to ∠B =
side opposite ∠B =
side opposite ∠C =
side adjacent to ∠C =

(Tunghayan ang mga sagot sa ibaba)

Matapos nating malaman ang mga parte o bahagi ng isang right triangle, handa na tayong kilalanin ang anim na trigonometric functions. Ang mga ito ay ginagamit upang hanapin ang nawawalang mga parte ng mga right triangles.

The Six Trigonometric Functions

1. Sine of an Angle

The sine of A is the ratio of the length of the side opposite A to the length of the hypotenuse. The sine of A is abbreviated as sin A.

Ang sine ng A (angle A) ay ang ratio ng haba ng gilid sa tapat ng A sa haba ng hypotenuse. Ang sine ng A ay dinaglat bilang sin A. Samakatuwid,


Pagmasdan ang pigura sa ibaba:




Ayon sa drawing sa itaas, makikita na:

sin Q = opposite/hypotenuse = RS/QS = 9/15

sin S = opposite/hypotenuse = QR/QS = 12/15

Pagmasdan ang pigura sa ibaba:



Ayon sa drawing sa itaas, makikita na:

sin D = opposite/hypotenuse = EF/DF = 24/26

sin F = opposite/hypotenuse = DE/DF = 10/26

2. Cosine of an Angle

The cosine of A (angle A) is the ratio of the length of the side adjacent to A and the length of the hypotenuse. The cosine of A is abbreviated as cos A. 

Ang cosine ng A (angle A) ay ang ratio ng haba ng gilid katabi ng A sa haba ng hypotenuse. Ang cosine ng A ay dinaglat bilang cos A. Samakatuwid,


Pagmasdan ang pigura sa ibaba:


Ayon sa drawing sa itaas, makikita na:

cos Q = adjacent/hypotenuse = QR/QS = 12/15

cos S = adjacent/hypotenuse =  SR/QS = 9/15

Pagmasdan ang pigura sa ibaba:


Ayon sa drawing sa itaas, makikita na:

cos D = adjacent/hypotenuse = DE/DF = 10/26

cos F = adjacent/hypotenuse = EF/DF = 24/26

3. Tangent of an Angle

The tangent of A (angle A) is the ratio of the length of the side opposite A and the length of the side adjacent to A.  The tangent of A is abbreviated as tan A. 

Ang tangent ng A (angle A) ay ang ratio ng haba ng gilid katapat ng A sa haba ng gilid kalapit ng A. Ang tangent ng A ay dinaglat bilang tan A. Samakatuwid,

                    tan A = length of side opposite  A
        length of side adjacent to A


Pagmasdan ang pigura sa ibaba:

Ayon sa drawing sa itaas, makikita na:

tan Q = opposite/adjacent = SR/QR = 9/12

tan S = opposite/adjacent =  QR/SR = 12/9

Pagmasdan ang pigura sa ibaba:


Ayon sa drawing sa itaas, makikita na:

tan D = opposite/adjacent = EF/DE = 24/10

tan F = opposite/adjacent = DE/EF = 10/24

4. Cotangent of an Angle

The cotangent of A (angle A) is the reciprocal of the tangent of A. It is the ratio of the length of the side adjacent to A and the length of the side opposite A.  The cotangent of A is abbreviated as cot A. 

Ang cotangent ng A (angle A) ay ang kabaliktaran ng tangent ng A. Ito ay ang ratio ng haba ng gilid kalapit ng A sa haba ng gilid katapat ng A. Ang cotangent ng A ay dinaglat bilang cot A. Samakatuwid,

                    cot A = length of side adjacent to A
        length of side opposite A


Pagmasdan ang pigura sa ibaba:


Ayon sa drawing sa itaas, makikita na:

cot Q = adjacent/opposite = QR/SR = 12/9

cot S = adjacent/opposite =  SR/QR = 9/12

Pagmasdan ang pigura sa ibaba:


Ayon sa drawing sa itaas, makikita na:

cot D = adjacent/opposite = DE/EF = 10/24

cot F = adjacent/opposite = EF/DE = 24/10

5. Secant of an Angle

The secant of A (angle A) is the reciprocal of the cosine of A. It is the ratio of the length of the hypotenuse and the length of the side adjacent to  A.  The secant of A is abbreviated as sec A. 

Ang secant ng A (angle A) ay ang kabaliktaran ng cosine ng A. Ito ay ang ratio ng haba ng hypotenuse sa haba ng gilid kalapit ng A. Ang secant ng A ay dinaglat bilang sec A. Samakatuwid,

                    sec A = hypotenuse                  
        length of side adjacent to A


Pagmasdan ang pigura sa ibaba:

Ayon sa drawing sa itaas, makikita na:

sec Q = hypotenuse/adjacent = QS/QR = 15/12

sec S = hypotenuse/adjacent =  QS/SR = 15/9

Pagmasdan ang pigura sa ibaba:


Ayon sa drawing sa itaas, makikita na:

sec D = hypotenuse/adjacent = DF/DE = 26/10

sec F = hypotenuse/adjacent = DF/EF = 26/24

6. Cosecant of an Angle

The cosecant of A (angle A) is the reciprocal of the sine of A. It is the ratio of the length of the hypotenuse and the length of the side opposite  A.  The cosecant of A is abbreviated as csc A. 

Ang cosecant ng A (angle A) ay ang kabaliktaran ng sine ng A. Ito ay ang ratio ng haba ng hypotenuse sa haba ng gilid katapat ng A. Ang cosecant ng A ay dinaglat bilang csc A. Samakatuwid,

                csc A = hypotenuse                  
      length of side opposite A


Pagmasdan ang pigura sa ibaba:


Ayon sa drawing sa itaas, makikita na:

csc Q = hypotenuse/opposite = QS/SR = 15/9

csc S = hypotenuse/opposite =  QS/QR = 15/12

Pagmasdan ang pigura sa ibaba:


Ayon sa drawing sa itaas, makikita na:

csc D = hypotenuse/opposite = DF/EF = 26/24

csc F = hypotenuse/opposite = DF/DE = 26/10

PAGSASANAY B

1. Pagmasdan ang drawing sa ibaba at sagutin ang mga tanong:




sin A =                sin C =
cos C =               cos A =
tan A =                tan C =

2.Pagmasdan ang drawing sa ibaba at sagutin ang mga tanong:




sin Y =                 sec Z =         
cos Y =                cot Z =
tan Y =                csc Z

3. If sin B = 8/3, then csc B = ______.

A. 8/3 B. 3/8 C. 3/3 D. 8/8

4. If tan W = 12/13, then 13/12 is ______.

A. csc W         B. sec W         C. cos W         D. cot W

5. Right Δ123 has sides 3, 4, and 5 units. The hypotenuse of the triangle is ______ units.

A. 3         B. 4         C. 5 D. 12

6. Right ΔJKL has sides 9, 12, and 15 cm. If ∠K is the right angle and side JK = 12 cm, then cot L = _____?

A. 9/12 B. 12/15         C. 9/15 D. 12/9

Tandaan

The two sides of the triangle that form the right angle are called its legs. The third side is called its hypotenuse.

The leg that helps form an acute angle in a right triangle is said to be adjacent to that angle.

The same leg is said to be opposite the other acute angle.

The hypotenuse is always the side opposite the right angle and it is the longest side.


Upang matandaan ang formula para sa sine, cosine, at tangent, alalahanin ito:
SohCahToa, kung saan ang S = sine, o = opposite, h = hypotenuse, C = cosine, at T = tangent. Kaya, 
Soh ==>sine A = o/h or opposite/hypotenuse
Cah==>cosine A = a/h or adjacent/hypotenuse
Toa==>tan A = o/a or opposite/adjacent


Tandaan din na:

Ang cotangent  ay kabaliktaran ng tangent . Kung ang tan A = opposite/adjacent,  ang cot A = adjacent/opposite.

Ang secant ay kabaliktaran ng cosine. Kung ang cos A = adjacent/hypotenuse, ang sec A = hypotenuse/adjacent.

Ang cosecant ay kabaliktaran ng sine. Kung ang sin A = opposite/hypotenuse, ang csc A = hypotenuse/opposite.

SAGOT SA PAGSASANAY










Saturday, October 9, 2021

Lesson 6 - Converting Degrees to Radians and Vice Versa: Introduction to Trigonometry

LESSON 6 – Converting DEGREES to RADIANS and vice versa

Matapos nating mapag-aralan ang mga uri ng linya, salikop o anggulo, trianggulo, complementary at supplementary angles, gayundin ang katuturan ng Pythagorean Theorem, sa leksyon 6 ay susubukin naman nating lubos na maunawaan ang degree at radian.



Sa araling ito, malalaman mo ang pagkakaiba sa pagitan ng dalawang yunit ng pagsukat na ginamit para sa mga anggulo: degree at radian. Malalaman mo rin kung paano i-convert ang isang unit sa isa pa.
Ang araling ito ay mahalaga sapagkat may mga problema na maaaring matugunan mo sa hinaharap na nagsasangkot ng pagsukat ng mga anggulo.

Pagmasdan ang bilog sa ibaba:


CIRCUMFERENCE = the yellow ring


The circumference is the distance around a circle. It is always equal to 360 unit (either  degree (o) or radian (rad)).

A degree is a unit of measurement equal to 1/360 of the circumference of a circle. 

From this, we can conclude that:

     90o = 90 (1/360) of the circumference = ¼ of the circumference 
   180o = 180 (1/360) of the circumference = ½ of the circumference 
   270o = 270 (1/360) of the circumference = ¾ of the circumference




The circumference of a circle = 2π (2 pi). (pi is pronounced as “pie”)
π (pi) = is a symbol that has a constant value. Ito ay katumbas ng 3.1416 o ≈ 3.1416 na nakuha matapos i-divide ang circumference sa 2 radius (o diameter).

 Hindi eksakto ang value ng pi kaya ginagamit ang simbolong ≈, na ang ibig sabihin ay “approximate”. 

There are π/180o or 0.01745 rad in 1°. So, to convert degrees to radians, we multiply the number of degrees by π/180o or 0.01745 rad. 
 
Ang isang degree ay may katumbas na π/180o o  0.01745 rad. Kung gayon, para ma-convert ang value ng degree sa radian, i-multiply lamang ang degree sa π/180o  o  0.01745 rad..

Mga Halimbawa
Convert the following degrees into radians.

1. 30o  = 30o (π/180o) = 3π/18 = π/6 rad
2. 90o  = 90o (π/180o) = 9π/18 = π/2 rad
3. 225o  = 225o (π/180o) = 45π/36 = 5π/4 rad
4.  74o = 74o (0.01745) = 1.2913 rad
5. 300o = 300o (0.01745) = 5.235 rad

There are 180o/π or 57.2956o  in 1 rad. Thus, to convert radians to degrees, we multiply the number of radians by 180o/π or 57.2956°.
 
Ang isang radian o 1 rad ay may katumbas na 180o/π  o  57.2956 degrees. Kung gayon, para ma-convert ang value ng radian sa degree, i-multiply lamang ang radian sa 180o/π  o  57.2956o.

Mga Halimbawa
Convert the following radians into degrees.

1. 3π/4 rad = 3π/4 (180o/π) = 540/4 = 135o
2. 5π/3 rad = 5π/3 (180o/π) = 900/3 = 300o
3. 11π/6 rad = 11π/6 (180o/π) = 1980/6 = 330o
4. 0.6 rad = 0.6 (57.2956o) = 34.3774o
5. 2π rad =  2 (3.1416) (57.2956o) = 360o

Tandaan

1. A degree is equal to 1/360 of the circumference of a circle.

2. A radian, if placed at the center of a circle, makes an arc equal to the radius of the circle.

3. p180° rad or .01745 rad = 1°

4. To convert degrees to radians, we multiply the number of degrees by π/180° or  0.01745.

5. 180°/p or 57.2956° = 1 rad.

 6. To convert radians to degrees, we multiply the number of radians by 180°/π or 57.2956°.


A pi (π) has an approximate value of 3.1416  or 22/7.  π =  circumference/diameter of a circle



Thursday, October 7, 2021

Lesson 5 - Triangles: Introduction to Trigonometry in Taglish

Lesson 5 - TRIANGLES



Bago natin suungin ang aralin tungkol sa triangle o trianggulo na siyang pinakabasehan ng Trigonometry, alalahanin nating muli ang ating mga napag-aralan na:


An angle is formed by two rays with a common endpoint. The two rays are called the sides of the angle and the common endpoint is called the vertex.

Angles are usually named using three capital letters of the English alphabet. But they can also be named using numbers or letters of the Greek alphabet.

protractor is an instrument used to measure an angle. The units of measurement for angles are degrees (°) or radians (r).

Angles are classified according to their measurements.

Acute angle an angle whose measurement is less than 90°.

Right angle an angle whose measurement is exactly 90°.

Obtuse angle an angle whose measurement is more than 90°

but less than 180°.

Straight angle an angle whose measurement is exactly 180°.

Reflex angle an angle whose measurement is more than 180°

but less than 360°.

If the sum of the measurements of two angles is 90°, they are complementary angles.

To find the measurement of the complement of a given angle, subtract the measurement of the given angle from 90°.

If the sum of the measurements of two angles is 180°, they are supplementary angles.

To find the measurement of the supplement of a given angle, subtract the measurement of the given angle from 180°.

After learning all about angles in the previous lesson, you are now ready to tackle more complicated figures such as triangles. This lesson will focus on the different kinds of triangles. The knowledge you will gain from this lesson will hopefully help you in solving real-life problems. 

Matapos mong malaman ang lahat tungkol sa mga anggulo sa nakaraang aralin, handa ka na ngayon upang harapin ang mas kumplikadong mga pigura tulad ng mga triangles. Ang aralin na ito ay magtutuon sa iba't ibang mga uri ng mga triangles. Ang kaalamang makukuha mo mula sa araling ito ay sana makatulong sa iyo sa paglutas ng mga problema sa totoong buhay.

Ano ang triangle?

A triangle is a polygon with three sides and three angles.

Ang trianggulo ay isang polygon na may tatlong gilid at tatlong anggulo.







Masdan ang triangle sa itaas. Ang simbolo para sa isang trianggulo ay DTatawagin nating  QRP ang pigura sa itaas. Ang sides o mga gilid ng QRP ay QR (RQ), QP (PQ), at RP (PR). Ang tatlong angles naman ay ÐQ,  ÐR, at ÐP.

What are the different kinds of triangles?

A. Triangles are classified according to the lengths of their sides.
Ang mga trianggulo ay kinaklase ayon sa haba ng mga sides/gilid nito.

1. A scalene triangle is a triangle with no congruent side. Congruent means having the same or equal measure.



In the above figure, PQ ≠ QR ≠ PR, so ΔPQR is a scalene triangle.

2. An isosceles triangle is a triangle with two congruent sides.

3. An equilateral triangle is a triangle with three congruent sides.




B. Triangles are also classified according to the kinds of angles that make them up.

1. A triangle with a right angle is called a right triangle. A right angle measures 90 degrees.


2. A triangle that is made up of three acute angles is called an acute triangle. An acute angle measures more than zero degrees but less than 90 degrees.



3. A triangle with an obtuse angle is called an obtuse triangle. An obtuse angle measures more than 90 degrees but less than 180 degrees.



In summary, triangles are classified according to the lengths of their sides and the angles that they make up. See the illustration below from  https://www.cuemath.com to understand and remember the concept:


Pagsasanay

        Upang matasa kung nauunawaan ang leksyon, sagutin ang mga sumusunod na katanungan:

1. Magkakasukat ang tatlong gilid o sides ng isang trianggulo. Ang triangle na ito ay tinatawag na __________ triangle.

A. right 
B. equilateral
C. isosceles
D. acute

2. Isa sa mga angles ng triangle na ito ay may sukat na 91 degrees. Ang triangle na ito ay isang ________ triangle.

A. right
B. acute
C. obtuse
D. isosceles

3. Ang isosceles triangle ay may magkakaparehong sukat ng _______ gilid o sides.

A. isa
B. dalawa
C. tatlo
D. apat

4. May tatlong acute angles ang triangle na ito na hindi magkakapareho ang sukat. ________ triangle ang tawag dito.

A. acute
B. scalene
C. obtuse
D. right

5. Ang mga sides o gilid ng triangle na ito ay iba-iba ang mga sukat. Ang tawag sa triangle na ito ay ________ triangle.

A. equilateral
B. isosceles
C. reflex
D. scalene

6. Ang sukat ng  mga angles ng isang equilateral triangle ay _________.

A. iba-iba
B. 30 degrees
C. 45 degrees
D. 60 degrees

7. Ang supplementary angle ng ÐY = 30 degrees ay _______ degrees.

A. 60
B. 90
C. 150
D. 330

8. Alin sa mga sumusunod na pares ang complementary angles?

A. Ð2  = 30o    |     ÐA = 30o
B. Ð3  = 35o    |     ÐB = 35o
C. Ð4   = 45o   |     ÐC = 45o
D. Ð5   =  90o      ÐM = 90o

9. Ang triangle na ito ay may dalawang gilid na magkakapareho ang sukat. _______ triangle ang tawag dito.

A. isosceles
B. equilateral
C. complementary
D. right

10. Ilang right angle mayroon ang isang right triangle?

A. wala
B. isa
C. dalawa
D. tatlo

Mga sagot sa pagsasanay

Monday, September 27, 2021

Sample of Essays for Reading and Writing Test for Revalida Batch 2020-2021 |English Proficiency Test

Bilang bahagi ng pagtatasa upang malaman kung ipapasa ang isang ALS completer, maliban sa kanyang Presentation Portfolio, siya ay isasabak din sa English Proficiency Test kung saan tatasahin ang kanyang kakayahang bumasa at sumulat (reading and writing) sa wikang Ingles.

Ang nasa ibaba ay ilan lamang sa mga sanaysay o essays na maaaring gamitin sa Reading and Writing sa panahon ng Revalida para sa Batch 2020-2021 para sa Elementary o Junior High School Level:


Adapting to Survive

                                   (Image from https://www.centennialparklands.com.au)


Living things adapt to their environment so they can survive. An organism adapts when it develops a behavior that makes it more likely to survive. It can also adapt by forming a physical characteristic or body part that helps it survive.

In a forest biome, some trees grow taller than the other plants around them. This lets them reach the sunlight. Growing taller is an adaptation that helps trees survive. Shorter plants have adapted with their behavior. They have learned to live in the shade with less sunlight. 

Animals in the forest have a wide variety of adaptations. Monkeys have long tails. They can use them almost like another hand. This helps them swing quickly through the tops of trees. They can even do this while holding their babies or gathering food. Giraffes need to reach leaves at the tops of tall trees. Having a long neck is an adaptation that allows them to do this.

Some animals’ adaptations prevent other animals from wanting to eat them. A skunk’s horrible smell makes larger animals choose something else to eat. Even plants sometimes protect themselves in this way. Roses and acacia trees both have dangerous thorns. The thorns prevent animals from eating their leaves.




        Answer the following questions based on the reading passage. Don’t forget to go back to the passage whenever necessary to find or confirm your answers. The sample answers are guides only. The answer should be a complete sentence.

1) What are the two main ways that an organism adapts?

by changing its behavior or its physical characteristics

2) What is one animal adaptation you read about in the passage?

a monkey’s tail or a giraffe’s neck or a skunk’s smell

3) Is the animal adaptation you chose a physical or behavioral adaptation?

trees grow tall or short plants learn to live with less sunlight or roses and acacia trees grow thorns

4) What is one plant adaptation you read about in the passage?

trees - physical; short plants - behavioral; roses and acacia trees - physical

5) Is the plant adaptation you chose a physical or behavioral adaptation?

answer depends on student’s choice


Competing for Resources


The resources of any one environment are limited. Depending on which plants and animals share the environment, there may not be enough of everything to go around. All organisms need water, food, and shelter to stay alive. These resources are beneficial, which means they are good for the organisms. When an environment is low on any of these things, organisms must compete for them. Those who get to the resources first have the best chance of survival. Being without water, food, or shelter for very long is detrimental, which means it is harmful to organisms.

The resources in an area determine how big the plant and animal populations can be. Sometimes there are too many living things in an area. The weakest of the populations will not be able to get the resources they need. As the weak die out, the populations get smaller. Finally, the area’s resources recover and can support them again. Sometimes people will capture members of large animal populations and move them. They take them to another location with less competition. This helps them the animals survive.

Sometimes the government will allow the hunting of large animal populations. Deer and rabbits can be good food sources for people. When there are too many of these animals in an area, they sometimes come into the cities looking for food. They often cause trouble. Hunting keeps the number of animals under control.


        Answer the following questions based on the reading passage. Don’t forget to go back to the passage whenever necessary to find or confirm your answers. The sample answers are guides only. The answer should be a complete sentence.

1) Why do organisms sometimes have to compete for resources?

because an environment may not have enough resources

2) What kinds of things are beneficial for organisms?

food, water, and shelter

3) What kinds of things are detrimental for organisms?

being without food, water and shelter

4) What happens when populations grow too large for an area?

The weaker ones can’t compete for resources and die out

5) Do you think hunting or relocation is a better solution for over-sized animal populations? Why?

Answer depends on student’s choice


Ecosystems


(Image from https://eschooltoday.com)

An ecosystem is all the things that interact in a specific area, whether they are living or non-living. Some examples of non-living things that support life in an ecosystem are light, air, soil, and water. Living things are the plants and animals, called organisms, that use those resources.

Each of the specific ecosystems in the world has its own conditions created by non-living things. These conditions determine what kinds of living things will be able to thrive there. Organisms can only thrive where their needs are being met. Everything in an organism’s environment has an effect on it. One ecosystem that allows many different kinds of organisms to thrive is a temperate zone. It is an area where the conditions never become too hot or too cold.

All the living things in an ecosystem are called a community. All of one specific kind of organism living in a community is called a population. All the tree frogs in a rainforest community are one population within the community. All the white birch trees are another population within the same community. All the jaguars are yet another rainforest community population.

All living organisms perform certain life processes. They take in nutrients like air, sunlight, water, and food. They use energy from those nutrients to grow and develop. They release energy by doing work and moving. They release waste products. They react to things in their environment. They reproduce, producing offspring, or babies, that are similar to themselves.


        Answer the following questions based on the reading passage. Don’t forget to go back to the passage whenever necessary to find or confirm your answers. The sample answers are guides only. The answer should be a complete sentence.

1) What is one example of a non-living thing in an ecosystem?

light, air, water, or soil

2) What are some of the life processes that living organisms do?

take in nutrients, use energy to grow, release energy, release waste, react to their environment or reproduce

3) What does population mean in a community?

one specific type of organism living in a community

4) When does an organism thrive?

when its needs are met

5) Why does a temperate zone support many varieties of organisms

because the conditions are not too hot and not too cold


Food Is Our Fuel


(Image from https://ualr.edu)

Everything that is alive needs energy. All animals get the energy they need from food.    People are animals. You can think about the human body as an amazing machine. It can do all kinds of wonderful things for us. Food is the fuel that helps keep the amazing machine running.

Plants use sunlight to make their own food. Animals are not able to do that. Some animals eat plants. Some animals eat other animals as meat. Some animals, like people, eat both plants and animals.

Since plants make their own food using sunlight, the sun’s energy is found in plants.  The sun’s energy is very strong. It loses a lot of its strength by the time it goes into a plant. 

When we eat plants, we get more of the sun’s energy than when we eat animals. That’s why it is good to eat fruits and vegetables. When an animal eats a plant, the energy is less strong. The animal also used its energy to find the plant to eat. When a second animal eats the first animal, it gets even less energy than the first animal got. The second animal used a lot of energy to find and chase its prey.

Like a car that has to be filled with gasoline, living things have to eat again and again. Instead of gasoline, living things use food as fuel.


        Answer the following questions based on the reading passage. Don’t forget to go back to the passage whenever necessary to find or confirm your answers. The sample answers are guides only. The answer should be a complete sentence. 

1) Where do all animals get their energy?

from food

2) Where do plants get their energy?

from sunlight

3) If our bodies are amazing machines, then food is our ______.

fuel

4) Why do we get more energy from eating vegetables than we get from eating meat?

because the sun’s energy is less strong in meat

5) If a third animal eats the second animal,  will it get more or less energy?

less energy

 

Have You Got The Time


(Image from https://stevekeating.me)

People today are always thinking about the time. There never seems to be enough time to do all the things we want to do. Believe it or not, there was a time before time was so important. It was enough to know that the sun was out. That meant it was daytime. During these days when the clock seems to control us, doesn’t that sound kind of nice?

Time can mean a lot of different things. That’s one way we know how important it is for us. We have so many words about it! The smallest amount of time we can measure is called a second. When you put 60 seconds together, you get one minute. If you take 60 minutes, you get one hour. The hands of the clock go all the way around twice in 24 hours, giving us one day.

If you want to look at time beyond one day, you leave the clock and look at a calendar instead. There are about 30 days in one month. Some months have an extra day; February has a couple less. There are 12 months in one year. Time never stops.


        Answer the following questions based on the reading passage. Don’t forget to go back to the passage whenever necessary to find or confirm your answers. The sample answers are guides only. The answer should be a complete sentence.

1) What are people always thinking about these days?

time

2) We have lots of different words about time. What does that show?

that it is important

3) How many hours are in one day?

24

4) How many seconds are in one minute?

60

5) How many months are in one year?

12

 

Magnetic Attraction

 


An object that attracts metals, especially iron, is called a magnet. The area near the magnet where it has enough power to attract things is called its magnetic field. The farther away from the magnet an item is, the weaker the magnetic fi eld is. When it is weak, it is less likely an object will become attracted to the magnet.

Magnets can be either permanent or temporary. A permanent magnet stays magnetized for a long time. A temporary magnet loses its magnetism after only a short time. You can even turn something made out of iron into a temporary magnet by rubbing it against a permanent magnet. The more you rub, the stronger your temporary magnet gets. However, the effects will wear off over time.

The two ends of the magnets are called magnetic poles. The poles are found at the ends of bar magnets and the tips of the horseshoe magnets. They are the strongest parts of the magnet. Each magnet has a north pole and a south pole. Opposite poles attract, or pull  toward each other. Poles that are the same repel, or push away from each other. A north pole and a south pole will pull toward each other. Two north poles will push away from each other. The same happens with two south poles. When you hold magnets, you can actually feel the push and pull effects of magnetism.

A special kind of temporary magnet uses electricity to create a magnetic field. It is called an electromagnet. An electromagnet can be an extremely strong magnet. However, it only acts like a magnet when it has electricity. A stronger electrical current will produce a stronger magnet. Unlike other magnets, an electromagnet can be controlled by a switch. When the switch turns the electrical current off the electromagnet loses its magnetism. Whatever the electromagnet was holding drops to the ground. We use this technology to operate large cranes that lift heavy metal objects, such as cars. Electromagnets are also used to make motors run in small appliances. Combining regular magnets and electromagnets makes it possible for electrical energy to be turned into energy of motion.


        Answer the following questions based on the reading passage. Don’t forget to go back to the passage whenever necessary to find or confirm your answers. The sample answers are guides only. The answer should be a complete sentence.

1) Explain the difference between a temporary magnet and a permanent magnet

A permanent magnet stays magnetized for a long time. A temporary magnet loses its magnetism in a short time

2) Would two north poles attract each other or push away from each other?

Push away

3) What is different about an electromagnet?

It uses an electrical current and can be turned off and on.

4) What do we use electromagnets for?

lifting heavy objects like cars

5) What does attract mean when speaking about magnets? _

pull toward each other

 

Plant Life Cycle


(Image from https://www.youtube.com/watch?v=XyT153p2uag by MNSB inward)

Every living thing goes through changes. Living things grow through different stages. Then they reach the end of their life cycles and die. There are many kinds of plants. Each kind has its own life cycle.

Many plants start their life cycles as a seed. The seed needs certain things or it will not grow into a plant. Sometimes seeds wait in the ground until they can get the things they need. They wait for warmth from the sun. They wait for water. When they have what they need, they start to grow. A tiny little sprout will push out of each seed. The sprouts stretch up until they poke through the dirt and into the air.

The plants continue to grow when they get sunshine and water. The stems grow taller and leaves unfold. More leaves and stems grow on the main stems. The adult plants grow flowers. The flowers of many plants make fruit. The fruit has seeds inside it so more new plants can grow.

New plants look like their parent plants. Seeds from a parent plant will grow into the same kind of plant as the parent. When a seed begins to grow, it is the beginning of another plant life cycle.

 

        Answer the following questions based on the reading passage. Don’t forget to go back to the passage whenever necessary to find or confirm your answers. The sample answers are guides only. The answer should be a complete sentence.

1) What is the process of living, growing, changing, and dying called?

life cycle

2) How do many plants begin?

As seeds

3) What two things does a seed need to have with it in the ground to be able to grow?

Sunshine and water

4) Where can you usually find seeds in an adult plant?

In the fruit

5) What kind of plant will a seed grow into?

the same kind as the parent plant


The Philippine Eagle 

Philippine Eagle

The Philippine Eagle has replaced the maya as our national bird. It is one of the three ln strongest eagles in the world. But it is in danger of extinction. Hunting and deforestation have number of Philippine Eagles to dwindle. Scientists have tried to increase their number by breedi captivity. The first eagle to be bred in captivity is Pag-asa. At 25 years old, Pag-asa is not yet released to the wild as she has developed dependency on her human keeper. 


Answer the following questions based on the reading passage.

1. The Philippine Eagle is in danger of extinction. It means this type of eagle will eventually _______.

A. disappear 
B. increase 
C. migrate
D. starve 

2. When birds are bred in captivity, they are _______.

A. allowed to freely fly in the wide forest
B. cared for in a safe environment
C. caught and sold as pets
D. given a diet of bread

3. What is responsible for the decrease in the number of Philippine Eagles? 

A. their migration to cooler countries
B. their transfer to warmer places
C. the activities of humans
D. lack of available food

4. Pag-asa is the name of the first eagle which ________.

A. was discovered first in our country.
B. was born in captivity.
C. was kept in the wild
D. was given as a gift.

5. What is the problem posed in the selection?  The Philippine Eagles _______.

A. are in danger of being gone forever
B. are dying because of a disease
C. migrate to other countries
D. are not growing fast

6.The purpose for writing the selection is to _________.

A. invite researchers to study the Philippine eagle.
B. make the reader proud of the Philippine eagle.
C. warn the hunters not to harm the Philippine eagle.
D. raise an alarm about the possible disappearance of the Philippine Eagle.

7. A good title for this selection is _________.

A. Help Save the Philippine Eagle
B. See the Rare Philippine Eagle
C. Breeding the Philippine Eagle
D. The Effects of Deforestation


Home to Millions of Fish

Coral Reefs

Coral reefs are found in shallow areas of tropical ocean waters. They are like beautiful underground gardens that grow in salty waters. Millions of fish and sea plants make their home in the reefs as these provide a safe sanctuary for them. They always allow small fish to hide from large predator fish. 

But many coral reefs are in trouble. Water pollution is destroying many reefs. Tourism likewise harms them. If reefs are damaged, we will lose many of our most beautiful fish.

Coral reefs are described as underground gardens because __________.

A. they are full of flowers
B. there are many sea plants
C. they have many enormous fish
D. there are many types of pebbles


DREAMS


We often say "Sweet dreams." but have you ever wondered why we dream? Some say that dreaming is our brain's way of exercising. While we sleep, our brain may be testing the connections and pathways to see if they are working well. Others believe that dreaming is our brain's way of sorting out problems. Problems that have not been addressed during the day are sometimes resolved in our sleep. Yet another explanation is that dreaming is our brain's way of fixing and organizing all the information we have. While sleeping, our brains have a chance to sort out the information that we want to keep from the stuff we no longer want. Still another idea is that dreams are just another form of thinking. Will we ever get to know the answer to this question? Maybe we should sleep on it.

Questions

1. Based on the selection, what does our brain exercise through sleeping?

a. the connections and pathways
c the content and concepts
b. the left and right hemispheres
d. the gray matter

2. Which of the statements does NOT show how dreams fix our problems?

a. As we dream, we constantly think about what we have learned or experienced
b. Our dreams help us focus on things we are unable to notice during the day
c. Our brain comes up with solutions in our sleep.
d. Our brain sorts and files information.

3. How does a brain-through dreams - perform the function of an office clerk?

a. It sorts information we need from what we don't need.
b. It files what we know into fixed categories.
c. It clears the board to store new information
d. It functions alone

4. Based on how it is used in the selection, which of the following words is a synonym for the word "resolved?"

a. accommodated 
b. reflected 
c. decided 
d. fixed

5. Which of the following statements is NOT true about the brain?

a. Our brain makes connections
b. Our brain never stops thinking.
c. Sleeping is our brain's way of shutting down
d. Our brain replays our experiences as we sleep.

6. Which question is the selection trying to answer?

a. What are the types of dreams?
b. What are our reasons for dreaming?
c. Are all dreams sweet?
d. How can we stop from dreaming?

7. In the selection, what does it mean to "sleep on it?"
a. ignore it
b. take a nap
c. think about it
d. forget about it

8. Which could be a good title for this selection?

a. Dreaming: Explained
b. Preventing Our Dreams
c. Interpreting One's Dream
d. Finding Solutions to Dreaming

Good Luck to your REVALIDA!