Dona Herweck Rice - Your World: Germs: Addition and Subtraction

0covercover.xhtmlcover1page0001page0001.xhtml22page0002page0002.xhtmlYour World Germs Addition and Subtraction33page0003page0003.xhtml44page0004page0004.xhtmlTable of Contents Little Sneaks 4 What Germs Do 8 No Germs 14 Problem Solving 20 Glossary 22 Index 23 Answer Key 2455page0005page0005.xhtmlLittle Sneaks They are all around! They are on you. They are inside you, too. What are they? Germs! Germs are too small to see with your eyes.66page0006page0006.xhtmlThis picture shows the shape of flu germs.77page0007page0007.xhtmlGerms are tiny and sneaky. They are on desks, chairs, and pencils. They are everywhere. But it can be hard to tell.88page0008page0008.xhtml99page0009page0009.xhtmlWhat Germs Do You cannot see germs because they are too small. You need a microscope. You might use this tool when you learn about germs.1010page0010page0010.xhtmlYou can see germs using a microscope. Let's Do Math Mr. Lee teaches science. He has 16 microscopes. He buys 10 more. How many microscopes does he have now? Solve with a number line.1111page0011page0011.xhtml1212page0012page0012.xhtmlGerms can make you sick. They can cause colds, fevers, and stomachaches.1313page0013page0013.xhtmlNot all germs hurt you. Some germs help. They help your body use food. This girl eats yogurt, which has good germs.1414page0014page0014.xhtmlThey also help get rid of waste. Good germs help your body break down food.1515page0015page0015.xhtmlNo Germs! You can help your body stay healthy. You can keep it safe from bad germs. You can help it fight germs, too.1616page0016page0016.xhtml1717page0017page0017.xhtmlWash your hands before you eat. Wash after you use the bathroom.1818page0018page0018.xhtmlUse soap and warm water when you wash.1919page0019page0019.xhtmlCover your mouth when you cough. Cover your nose and mouth when you sneeze. Use a tissue or the inside of your elbow. Then, wash your hands again. Goodbye, germs! Let's Do Math Rosa has 60 tissues. She has a cold and uses 20 tissues. How many tissues does she have left? Solve with groups of 10.2020page0020page0020.xhtmlThis girl covers her mouth and nose while sneezing.2121page0021page0021.xhtmlProblem Solving A class pretends that glitter specks are germs. They put the "germs" on their hands. They watch the germs spread. At the end of the day, there are... 31 germs on a pencil 47 germs on a chair 82 germs on a desk Solve the problems with the hundreds chart. 1 Pia's hands are covered with germs. She spreads 10 more germs onto each item. How many germs are on each item now? 2 Ty wipes 30 germs from the desk after Pia leaves. How many germs are left?2222page0022page0022.xhtml2323page0023page0023.xhtmlGlossary cough to force air up through the throat and out the mouth in a short, noisy burst healthy not sick microscope a tool that makes tiny objects bigger and easier to see sneaky not seen or known by others sneeze to force air through and out the nose in a short, noisy burst waste substance that is not needed or wanted2424page0024page0024.xhtmlIndex cough, healthy, microscope, sick, sneeze, wash,2525page0025page0025.xhtmlAnswer Key Let's Do Math! page 9 : 26 microscopes 16 10 page 18 : 40 tissues Problem Solving 1 pencil : 41 germs; chair : 57 germs; desk : 92 germs 2 62 germs2626page0026page0026.xhtmlMath Talk 1 What patterns do you see on a hundreds chart when adding and subtracting 10? 2 How do you choose whether to add or subtract when solving a word problem? 3 What strategies can you use to mentally add and subtract 10? 4 Lila writes : 30-10 = 2 tens Do you agree with her solution? Why or why not?2727page0027page0027.xhtmlYour World Germs Addition and Subtraction Germs. Everybody has them. Add and subtract with tens to learn how some germs can help or harm people!28

Your

World

Germs

Addition

and

Subtraction

Table

of

Contents

Little

Sneaks

What

Germs

Do

No

Germs

Problem

Solving

Glossary

Index

Answer

Key

Little

Sneaks

They

are

all

around

!

They

are

on

you

.

They

are

inside

you

,

too

.

What

are

they

?

Germs

!

Germs

are

too

small

to

see

with

your

eyes

.

This

picture

shows

the

shape

of

flu

germs

.

Germs

are

tiny

and

sneaky

.

They

are

on

desks

,

chairs

,

and

pencils

.

They

are

everywhere

.

But

it

can

be

hard

to

tell

.

sneaky

What

Germs

Do