Unit 3: Addition and Subtraction to 18

Dear Grade 2 Families,

In this unit, your child will be developing strategies for adding and subtracting 1-digit numbers.

The Learning Goals for this unit are to:

• Develop and use mental math strategies to add and subtract two 1-digit numbers, including zero.
• Look for patterns in digits when adding and subtracting.
• Understand and use the relationship between addition and subtraction; for example, 2+7=9 and 9-7=2
• Find out if 2 sides of a number sentence are equal or not equal. 10=6+4 and 3+6 does not =10.

You can help your child achieve these goals by doing these Home Connection activities!

1. Share addition and subtraction story problems about things in your neighbourhood. For example, "There are 15 houses on our street. 9 of them have a garage. How many do not have a garage?"

2. Have your child build a set of 5 to 9 pennies and then add 1, 2, or 3 pennies to that number. Have your child tell the addition sentence. Then, take the same number of pennies away. Have your child tell the subtraction sentence.

3. With your child, look around the house for items that come in equal sets. Discuss that happens if you add items or take a few items away. Are the sets still equal?

4. When you set the table, have your child add groups of items on the table (forks, knives, glasses). Try adding them in a different order. Have your child explain why the order doesn't matter.

5. Have your child take a number if cans from the cupboard. Use a cloth to hide some of them. Have your child explain how addition can be used to find out how many are covered.

6. When you spend leisure time with your child. pose different missing parts problems. Have your child explain how he or she figured out the answer. (9 dogs are ready to compete in a dog show. 18 signed up. How many more dogs needs to come?)

7. When you solve everyday subtraction problems , ask your child questions such as, "What do we already know? " "What piece is missing?"

8. Ask your child to tell a number story using a double or near doubles.

9. Watch for situations where your child can use a strategy to add or subtract 1 digit numbers.