2. Smart Science
GRADE 1
TEXTBOOK
Philippine Copyright 2009 by DIWA LEARNING SYSTEMS INC
All rights reserved. Printed in the Philippines
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ISBN: 978-971-46-0085-0
REVIEWER
Marina Balce was a former assistant dean and associate professor at the College of Education, La
Salle College–Antipolo. She taught biological sciences for Psychology students and thesis writing for
graduating Education students in the same college. She was also a Trainee of the Japan International
Cooperation Agency (JICA) at the Aichi University in Nagoya, Japan, where she attended a special
training on Practical Work in Elementary School Science. Dr. Balce finished her bachelor’s degree in
Secondary Education major in Biology at the University of the East–Manila. She has a master’s degree
in Biology Education from the De La Salle University–Manila and a doctorate in Science Education
major in Biology from the University of the Philippines–Diliman.

3. To the Learner
Do you ask yourself questions about the world you live in?
Do you wonder about what lies beyond the blue skies or what
rests below the seas? Do you ask questions about the blooming
trees and colorful flowers you see, the heat and cold you feel,
or the various scents you smell? Do you wonder about the sun,
the moon, and the stars? Your young, active mind has so many
questions because you are curious about so many things.
This book will help you discover the answers to the
questions you have about yourself, the world, and everything
beyond it. This book will be your constant companion as you
unlock the many mysteries of life through various learning
experiences. Moreover, this book will teach you how to apply the
wonders of science to your day-to-day activities.
Let this book help you find the answers to the questions you
have about yourself, your world, and your universe. Let this take
you a step closer to understanding life and in discovering the
wonders of science!

4. Unit I You and Your Body
Chapter 1 Your Body and Your Needs
Lesson 1 Parts of Your Body .....................................................................2
Lesson 2 You Can Do Many Things Using the Different Parts of Your
Body ......................................................................................... 7
Lesson 3 Caring for Your Body ...............................................................10
Lesson 4 Eating Healthy Foods ...............................................................13
Lesson 5 Your Body Needs Clean Air and Water ....................................18
Lesson 6 You Need Clothes to Protect Your Body ..................................23
Lesson 7 You Need a House to Live In ...................................................27
Lesson 8 You Need Rest, Exercise, and Recreation .................................32
Think Back ............................................................................................... 37
Measure Up! ............................................................................................... 37
Chapter 2 Body Changes in a Growing Child
Lesson 1 You Get Taller and Heavier as You Grow ................................40
Lesson 2 You Get Bigger as You Grow ...................................................44
Lesson 3 You May Be Alike with Others in Some Ways .........................48
Lesson 4 You May Be Different from Others in Some Ways ...................52
Lesson 5 Safety All the Time ..................................................................56
Think Back ............................................................................................... 61
Measure Up! ............................................................................................... 61
Unit II Animals and Plants
Chapter 3 Animals around You
Lesson 1 Animals Are Everywhere .........................................................66
Lesson 2 Body Parts of Animals..............................................................70
Lesson 3 Changes in Growing Animals ..................................................75

5. Lesson 4 Needs of Animals ....................................................................80
Lesson 5 Movements of Animals ............................................................87
Lesson 6 Places Where Animals Live .....................................................92
Lesson 7 Importance of Animals ............................................................97
Think Back ............................................................................................. 102
Measure Up! ............................................................................................. 102
Chapter 4 Plants around You
Lesson 1 Describing Plants...................................................................106
Lesson 2 Parts of Plants ........................................................................110
Lesson 3 Similarities and Differences in Some Plants ...........................114
Lesson 4 Kinds of Plants .......................................................................119
Lesson 5 Needs of Plants .....................................................................124
Lesson 6 Places Where Plants Grow ....................................................130
Lesson 7 Importance of Plants ..............................................................134
Think Back ............................................................................................. 139
Measure Up! ............................................................................................. 139
Unit III Matter, Energy, and Force
Chapter 5 A Closer Look at Matter
Lesson 1 Matter Everywhere ................................................................142
Lesson 2 Forms of Matter .....................................................................146
Lesson 3 Color and Smell of Matter......................................................152
Lesson 4 Matter Occupies Space ..........................................................156
Lesson 5 Measuring Volume ................................................................162
Lesson 6 Measuring Mass.....................................................................166
Think Back ............................................................................................. 169
Measure Up! ............................................................................................. 169

6. Chapter 6 Energy and Forces
Lesson 1 Uses of Heat ..........................................................................172
Lesson 2 Uses of Light .........................................................................178
Lesson 3 Uses of Sounds ......................................................................185
Lesson 4 Push and Pull ........................................................................191
Think Back ............................................................................................. 196
Measure Up! ............................................................................................. 196
Unit IV The Earth and the Sun
Chapter 7 The Earth
Lesson 1 What Does Earth Look Like? ..................................................200
Lesson 2 Earth’s Water Bodies..............................................................205
Lesson 3 Earth’s Landforms ..................................................................210
Lesson 4 Air Everywhere ......................................................................215
Lesson 5 Kinds of Weather ...................................................................218
Lesson 6 Earth Provides Our Needs .....................................................223
Lesson 7 You Are a Caretaker of Earth ..................................................227
Think Back ............................................................................................. 233
Measure Up! ............................................................................................. 233
Chapter 8 The Sun
Lesson 1 Big Ball of Fire: The Sun ........................................................236
Lesson 2 The Sun Warms Earth ............................................................240
Lesson 3 Protection from Strong Sunlight .............................................244
Think Back ............................................................................................. 247
Measure Up! ............................................................................................. 249
Bibliography ................................................................................................... 249

7. How well do you know your body? How should you take
care of it? What are your basic needs? What are the changes that
will happen to your body as you grow older? Learn the answers
to these questions and more in this unit.

8. Chapter 1
Your Body and Your Needs
Your body consists of different parts. These parts help you do
activities at home and in school. Each body part is important, so
it has to be cared for.
Lesson 1
Parts of Your Body
Find Out
1. What are the three main parts of your body?
2. What are your other body parts?
3. How do you prepare yourself for school?
Rita and Erik wake up
early during school
days. They are always
excited to go to school.
This is how they prepare
themselves for school.
Rita eats a healthy breakfast
before going to school.
2 Smart Science 1

9. She takes a bath and brushes her
teeth. She combs her hair, too.
She wears her clean school uniform. Now,
Rita is ready to go to school.
Erik is also ready to
go to school. He has eaten
his breakfast. He has also taken a
bath. His hair is neatly combed. His
fingernails are cut short. He wears
clean socks and shoes.
How about
you? How do you
head
prepare for school?
Do you know how to clean
upper your body? What are the
trunk
limbs different parts of your body?
lower Just like Rita and
limbs
Erik, your body has parts,
too. There are three main
parts of the body: the
head, the trunk, and the
The main parts of the body limbs.
You and Your Body 3

10. What are the parts of your head? The top and back of your
head are covered
with hair. On its
front is your face. hair
What can forehead
you find on your
face? You have eyebrow
eye
your forehead, ear
eyebrows, eyes, cheek
nose
nose, mouth,
mouth teeth
cheeks, and chin. tongue
Inside your mouth
chin
are your teeth and neck
tongue. The parts of the head
Look at the sides of your
head. There, you can find your
shoulder ears. Right below your face is
chest your neck. Your neck connects
your head to your trunk.
abdomen
What are the parts of your
trunk? It is composed of your
shoulders, chest, and abdomen.
The parts of the trunk
4 Smart Science 1

11. You have two sets of limbs—
the upper limbs and the lower upper
limbs arm
limbs. Your upper limbs are elbow
forearm
composed of your arms, elbows, wrist
forearms, wrists, and hands. You hand
can find your fingers and palm on lower
limbs thigh
your hands. knee
leg
Your lower limbs are ankle
composed of your thighs, knees, foot
legs, ankles, and feet. Your toes are
part of your feet. The parts of the limbs
Explore
Name Game
Look at Rita and Erik. Name the parts of their bodies pointed
by the arrows.
5.
1.
6.
2.
7.
3. 8.
4.
Choose a partner. Name his or her body parts.
You and Your Body 5

12. Math
Keep in Mind Look at yourself in the mirror.
Name parts of your body on the
Your body is made up left side and those on the right side.
of different parts. The three What do you notice? Your body has
main parts of your body are parts that come in pairs. You have
the head, the trunk, and the two eyes, two ears, two hands, and
limbs. two feet. Can you identify other
body parts that come in pairs?
Challenge Yourself
Draw the missing parts of the body. Label the parts that you
have drawn.
6 Smart Science 1

13. Lesson 2
You Can Do Many Things Using
the Different Parts of Your Body
Find Out
1. What activities can you do using your different body parts?
2. How do body parts work together?
Rita and Erik are
classmates. When they
have a project in class,
they work together to
finish it. Like Rita and
Erik, your body parts
work together so you can
do activities like playing,
studying, and eating.
Rita and Erik use
their body parts as
they play. Rita uses
her eyes to see the
ball. She uses her legs
and feet to run after
the ball. She uses her
arms and hands to
catch the ball.
You and Your Body 7

14. Erik uses his legs to run to the next base. He uses his arms
to reach for his teammate’s hand. He
uses his eyes to watch the other
team’s moves. He uses his
ears to listen to what his
teammates want him to do.
Explore
Can You Do These?
1. Look at the picture of Rita below. Draw Rita’s face in the box
with your eyes closed.
2. Follow the instructions.
a. Hold a fruit with your hands
(for example, an apple). Take
a bite from the fruit.
b. Put down the fruit on a plate.
c. Try eating the fruit again without
using your hands.
8 Smart Science 1

15. Were you able to draw Rita’s face with your eyes closed?
Were you able to eat the fruit easily without using your hands?
You use different body parts in doing many activities. You
can write easily if you use your hands and your eyes. When
eating, you use your mouth. You also use your hands to hold the
food. You use your nose to smell the food.
Keep in Mind
You use different body parts to do many activities faster and
easier.
Challenge Yourself
Which body parts work together in each activity? Encircle
the letter of your answer.
a. nose, hands
1.
b. eyes, hands
c. mouth, feet
d. ears, wrist
2. a. hands, ankles, nose
b. arms, legs, eyes
c. shoulder, feet, hair
d. knees, nose, eyes
3. a. abdomen, ears, feet
b. hands, feet, ears
c. arms, legs, eyes
d. mouth, chest, arms
You and Your Body 9

16. Lesson 3
Caring for Your Body
Find Out
How should you take care of your body?
After school, Rita and Erik go straight home. When they
reach home, both of them do things to take care of their body.
After eating dinner, Rita flosses and brushes her teeth. She
also cleans her tongue with a tongue cleaner. Before going to
bed, she washes her face and her body. She also changes her
clothes. Erik does the same things. Both of them know that they
need to take care of their bodies.
10 Smart Science 1

17. Explore
Are You Clean?
Answer each question below. If your answer is Yes, draw a
happy face ( ) in the circle. If your answer is No, draw a sad face
( ).
1. Do you take a bath every day?
2. Do you clean your ears regularly?
3. Do you always clean your nose?
4. Do you brush your teeth after eating?
5. Do you always comb your hair?
6. Do you cut your fingernails and toenails short?
7. Do you wash your hands after using the toilet?
8. Do you wear clean clothes?
9. Do you wear clean socks?
10. Do you wear clean shoes?
If you answered Yes
to all the questions, you are
taking good care of your
body.
Your body should be kept clean at all times.
Keeping yourself clean is one way of taking care of
your body. It also means you love yourself.
You and Your Body 11

18. If you do not take good care of yourself, germs will get into
your body. Germs are tiny harmful living things. They can make
you sick when many of them live in your body.
Keep in Mind
Take good care of your body by keeping it clean at all times.
Challenge Yourself
Which should you use to clean your body parts? Draw a line
to connect the body part to the appropriate cleaning tool.
1.
2.
3.
4.
12 Smart Science 1

19. Lesson 4
Eating Healthy Foods
Find Out
1. What are the three basic food groups?
2. What are the examples of foods belonging to each group?
Rita and her
family are out on
a picnic. Can you
tell the foods that
they have? All of
these foods are
healthy.
Food is one of
the basic things you
need.
You need healthy
foods to make your
body fit and strong.
What is your favorite
food? Do you eat
healthy foods?
You and Your Body 13

20. There are three basic food groups.
The first basic food group is called “go” foods. Go foods give
you energy for work and play. Bread, pasta, rice, and cake are
examples of go foods. These foods are sweet and starchy. They
are rich in carbohydrates.
What go foods do you usually eat?
Examples of go foods
The second basic food group is called “grow” foods. Grow
foods are rich in protein that helps you grow tall and makes your
body grow bigger. Meat, fish, and chicken are examples of grow
foods.
What grow foods did you eat for breakfast?
Examples of grow foods
14 Smart Science 1

21. The foods that belong to the third basic food group are rich
in vitamins and minerals. They are called “glow” foods. They
include vegetables and fruits. They keep your eyes, hair, and skin
healthy. They also keep your teeth and bones strong. Do you eat
fruits and vegetables?
What are your favorite glow foods?
Examples of glow foods
Go, grow, and glow foods are all important to a growing
child like you. A healthy meal includes the right amount of food
from all the food groups.
What food did you have for breakfast? What food groups are
included in your meal?
You and Your Body 15

22. Explore
Go, Grow, and Glow!
Do the following with
your group mates.
1. Mold clay into the shape
of your favorite foods.
2. Classify the foods you
made. Are they go, grow,
or glow foods?
If your favorite foods belong to the basic food groups, you
will grow healthy.
Keep in Mind
Your body needs go, grow, and glow foods. These will help
you grow strong and healthy.
Dear Parents,
Your child is learning about the foods he or she needs to become strong and healthy. As
your child eats, tell him or her to identify the go, grow, and glow foods in his or her meal.
16 Smart Science 1

23. Challenge Yourself
Encircle ( ) the go foods. Check ( ) the grow foods.
Box ( ) the glow foods.
You and Your Body 17

24. Lesson 5
Your Body Needs
Clean Air and Water
Find Out
Why do you need clean air and safe water?
After the picnic,
Rita’s father showed
her the whole park.
“It is good to visit
clean places like this.
Here, you breathe in
fresh air,” Rita’s father
said.
As they passed by
the bridge, they saw
clean water flowing through the creek. “Just like the fish, we need
clean and safe water, too,” explained Rita’s father.
Clean air is important
for you to live. You need
clean air even when you are
sleeping. Clean water is also
important. You need clean
water for you to stay healthy
and strong.
18 Smart Science 1

25. Explore
Inhale, Exhale
1. Inhale and then exhale.
2. Close your mouth. Gently pinch your
nose for about 10 seconds. Have
your seatmate count from 1 to
10 for you. Remove your hand
from your nose.
3. Now, breathe deeper. Try to
hold your breath for as long as
you can.
What did you feel as you pinched
your nose? For how many seconds do you think you can hold
your breath? What would happen if you cannot breathe?
You breathe all the time. Air
enters and leaves your body
through your nose. But you can
also breathe through your
mouth. You can breathe
through your mouth when
you have a clogged nose.
After doing a strenuous
activity, you also use
your mouth to breathe out.
Have you seen swimmers hold their head up to the surface
of water from time to time? They do that to get air. Swimmers use
their nose and mouth to breathe air.
You and Your Body 19

26. Air that contains too
much dirt can make you sick.
Factories and vehicles give off
smoke. Smoke contains dirt
and other harmful materials
that make the air dirty and not
fit to breathe in.
Did you know that
plants breathe, too?
Plants take in carbon
dioxide and release
oxygen. Carbon dioxide is
the gas humans and animals
give off. Oxygen is the gas
humans and animals need
to live. By absorbing carbon dioxide and giving off oxygen, plants
help clean the air.
You can help maintain clean air by planting trees and caring
for plants.
Like what Rita’s father said,
you need safe water, too. All living
things need water.
To stay healthy, you need to
drink at least eight glasses of liquids
every day. Examples of liquids
include water, juice, and soup.
Always drink clean water. Dirty water is
not safe because it can make you sick.
20 Smart Science 1

27. You also need clean
water to keep your body
clean. You use water
in taking a bath and in
brushing your teeth.
Water is also used in
household chores such
as washing dishes
and clothes.
What other uses
of water do you
know?
Check IT out!
Did you know that there is a device that can
clean drinking water? It is called a water purifier. You
usually see water purifiers at home, in school, and in
restaurants. It separates dirt and other harmful materials
from the water through a filter.
Clean and safe water is important to everyone. It
should be used properly. It should not be wasted.
Visit http://www.ecokids.ca/pub/eco_info/topics/
water/water/play_waterconserve.cfm. Click on any part of
the house to learn how to use water wisely around the house.
Keep in Mind
You need clean air and safe drinking water.
You and Your Body 21

28. Challenge Yourself
Cross out ( ) the pictures that show dirty air or water.
22 Smart Science 1

29. Lesson 6
You Need Clothes
to Protect Your Body
Find Out
1. Why do you need clothes?
2. How do clothes protect you?
It was a warm Saturday
morning. Erik went to Rita’s
house to help her in her
garden. Erik was wearing clothes for
gardening. Rita had changed into her gardening clothes, too.
Rita and Erik both wear clothes that
cover their arms and legs. These clothes
protect them from insects and plants in
the garden.
They also wear gloves to protect
their hands. Gloves also keep their hands
clean while they till the soil. Rita and
Erik also wear hats to protect themselves
from the glare and heat of the sun.
Clothes protect your body from
heat and cold. There are clothes
that keep your body cool. There are
clothes that keep your body warm.
Clothes can also protect you from
insect bites. They also keep your skin
from rubbing against rough surfaces. They prevent cuts from
sharp objects.
You and Your Body 23