• Strategies for Learning Addition and Subtraction Facts Addition and subtraction are inverse operation and students need to understand the relationship between the two.  Much time is spent at school learning about this relationship, and seeing the patterns in numbers.

Vocabulary is an important part of this process. The numbers that we add to get an answer are called addends .  The answer when 2 numbers are added is called the sum .  The answer to a subtraction fact is called the difference .

Ways to Learn these Facts

1.Ten Frame:

Starting in kindergarten, students learn to use the ten frame as a set of 10 units to develop the idea of how many 10 is.  The rows of 5 help students see the 2 sets of 5 in 10, and can use these for sums.  You can do things like filling 6 spaces and asking, "How many are full??  How many are needed to fill the ten frame?  How do you know?"

2. Double ten frames:  Using 2 ten frames, children can work with addition and subtraction combinations through 20.

3. Dot Patterns :  Dominoes and dice have patterns of dots on them already and can be used to add numbers.Students should learn to recognize these patterns and practice adding.  Another way to use dice:  play with a rule.  Using one die, ask the child to find the answer to "1 more" or "2 less" (or whatever the rule is) than the number of dots on the other die.

4. Making Ten :  The concept of "10" is a crucial idea in much of mathematics.  It helps students understand place value, operations on multi-digit numbers, decimals, and many other concepts.  Play a card game Tens Go Fish.  Students must ask for (by name) a card that will add to 10 with one of their own.  Ex.  I see I have a 4, so I ask for a 6.  Play a game of On and Off.  Students have 10 objects and drop them on a piece of paper.  Record how many land on and off the sheet by writing the number sentence.  Ex. 3 on the paper, 7 off the paper:  3 + 7 = 10.

5. Flash Cards:   Have your child sort them into 2 piles, "facts I know" and d "facts I don't know".  In the second pile, look at each one and think about ways to help remember it.  (Ex. 7 + 6 = 13 because 7 + 7 = 14, and 1 less is 13.)

1. One more, two more: learning that adding 1 just means counting 1 more.  Adding 2 just means counting 2 more.

2. The larger number  first: .  Have your child name the larger number first in an addition problem, and count on from there.  Ex. 2 + 5.  Start with 5 and count 2 more.

2. Doubles:   Ex. 4 + 4, 6 + 6, etc.  Here is a song students have learned about doubles. (Tune:  The Ants Come Marching)

2 plus 2 is 4 you know, hoorah, hoorah,

3 plus 3 is 6 you know, hoorah, hoorah.

4 plus 4 is 8 you know,

5 plus 5 is 10 you know,

And we all know that adding with doubles is no trouble at all.

Rah, rah, rah, rah,

6 plus 6 is 12 you know, hoorah, hoorah,

7 plus 7 is 14 you know, hoorah, hoorah.

8 plus 8 is 16,

9 plus 9 is 18,

And we all know that adding with doubles is no trouble at all.

Rah, rah, rah, rah.

Rah, rah, rah, rah.

3. Adding  Zero :  Students learn that when zero is added, you get the same number you started with, because zero is none.

4. Near doubles :  Relate these facts to the doubles plus one more.

Ex. 4 + 5, 6 + 7, etc.

Ways to Reinforce Subtraction Facts

1. Relating to Addition :  Ex. 7 - 3 = ? can be found by thinking 3 + ? = 7

2. One less, two less :  Learning that subtracting 1 just means counting back 1, and subtracting 2 just means counting back 2.

3.  All but one :  Ex. 8 - 7, 5 - 4, etc.  Students recognize that when we take away 1 less than the first number, we have 1 left.

4  Ten Frames :  These can be used for subtraction in much the same way as addition.