Grade 2

Tips for Helping at Home

•

Questions to ask:

What is it that you don’t understand (have

the student be specific)?

What information do you need?

What strategies are you going to use?

Can you guess and check?

Does this make sense?

What can you do to

explain your answer

to show others what

you are thinking?

Does your answer

seem reasonable?

•

Encourage your child to use his or her own

strategies for addition and subtraction. We will

use many in class.

•

For homework, your child will be writing various

types of story problems. Ask your child to tell you

about strategies he or she uses to solve these

problems. Encourage your child to use words,

pictures and numbers in any explanation.

•

Your child will also bring home some of the

games that we are playing during math class.

Take some time to play these games with your

child.

•

Children will be working with problems involving

money. Use some change to investigate ways to

make $1 or $2 with your child.

Website

http://www.everett.k12.wa.us/math/Second%20Grade

Mathematical Emphasis

Investigation 1—Combining and Separating

•

Developing models of addition and subtraction situations

•

Solving problems using numerical reasoning

•

Recording solution strategies

•

Understanding horizontal and vertical notation for addi-

tion and subtraction

Investigation 2—Working with 100

•

Becoming familiar with the structure and patterns of the

number system from 1 to 100.

•

Using coins as a model for adding and subtracting multi-

ples of 5 and 10.

•

Using the 100 chart as a tool for combining and compar-

ing numbers

•

Developing strategies for addition and subtraction

Investigation 3: Finding the Missing Part

•

Developing ways to approach different sorts of addition

and subtraction situations

•

Recognizing and solving problem structures with a vari-

ety of givens and unknowns

•

Solving problems using numerical reasoning

•

Creating situations for equations

Investigation 4: Adding Up to 100

•

Working with 100 and combinations of numbers that

equal 100

•

Adding strings of numbers by “chunking” or grouping

numbers that go together

•

Writing a story that reflects an addition equation

Investigation 5: Addition and Subtraction Strategies

•

Developing strategies for comparing two quantities

•

Calculating the distance between two numbers using the

100 chart

•

Developing ways to approach different types of addition

and subtraction situations.

Addition and

Subtraction

---

About the Mathematics In This Unit

In this unit, we will be working on addition and

subtraction. We will be working with 5’s, 10’s,

20’s, and 25’s and on ways to make 100. We

will also work on solving story problems and de-

ciding what operation to use to solve a problem.

Look for addition and subtraction situations at

home and share them with your child. For exam-

ple, if you bake a batch of cookies and you set

some aside for school lunches, how many cook-

ies will be left for the family to eat? You and

your child might compare the ages of the people

in your family: How much older are you than

your child? Or if you have 26¢ in your pocket

and you want to buy a snack that costs 55¢,

how much more money do you need?

One thing to keep in mind with these problems

is the size of the numbers. Numbers under 100

are about the right size for most second grad-

ers. Some children may be comfortable using

counters to solve problems, while others might

want to write their thinking on paper or solve

problems mentally.

Economopoulos, K. Investigations in Number, Data and Space:

Putting Together, Taking Apart. Dale Seymour Publications, 1998.

Vocabulary

equation

- a mathematical sentence

where the right side of the equals sign

has the same value as the left

example: 3 = 2 + 1

expression

- one or more numbers

and/or operation symbols

example: 5 + 8

multiple

- numbers landed on when

skip counting by a specific number.

example: Some multiples of 5 are 10,

15, 20, 25,

number string

- addition problem with

more than two addends.

examples: 2 + 9 + 1 + 2 =

5 + 6 + 4 + 10 + 5 =

10 + 10 + 10 = 30

Glossary

http://www.amathsdictionaryforkids.com/

Game

Get to 100

Materials:

Multiples-of-5 number cubes (2) or a set

of Multiples-of-5 Cards, 100 chart (for each player),

game piece (for each player), paper

Multiples-of-5: 5, 10, 15, 20, 25, 30 (need two sets)

Players:

2 or 3

How to Play

The object of the game is to reach 100 on the 100

chart.

1. Each player puts a game piece to the left of

number 1.

2. Take turns. Roll the number cubes or draw two

number cards and move that many spaces on

the 100 chart.

3. Record your move on paper. For example, if

your first roll is 5 and 15, write 5 + 15. If your

next roll is 10 + 5, move that many spaces and

add these numbers to your recording so that you

have 5 + 15 + 10 + 5. Your game piece should

be at 35.

4. Continue play, recording your moves each time.

5. You can use just one of the amounts on the

number cubes or cards to land directly on 100.

6. When you reach 100, check your moves by add-

ing all the numbers on your paper. If the sum

does not equal 100, move your game piece back

to the total number and continue play.

7. If the numbers do add to 100, move your game

piece back and play again.