Addition Tips and Tricks

 

Here are lots of "thinking tricks" you can use to make addition easier.

Use the ones that make sense to you!

Count From A Number Upwards

Example: 6 + 3

 

   
 

Think "6 ... 7, 8, 9"

Hint: start from the larger number.

Example: 2 + 6

HARD Start from 2 and count 6: Think "2 ... 3, 4, 5, 6, 7, 8"
EASY Start from 6 and count 2: Think "6 ... 7, 8"

Jump Strategy

We can also count by 2s or 10s, or make any "jumps" we want to help us solve a calculation.

Example: 4 + 12

Jump Strategy

Think "4 ... 14, 15, 16"

Adding Up To Ten

See if any of the numbers add up to 10. They don't have to be next to each other.

Example: 7 + 8 + 3 + 2 + 5

7+3 is 10,

8+2 is another 10, which makes 20,

Plus 5 is 25

Do The Tens Last

Break big numbers into Tens and Units, add the Units, then add on the Tens.

 

Example: 14+5

Break the "14" into Tens and Units: 10 + 4

Add the Units: 4 + 5 = 9

Now add the Tens: 10 + 9 = 19

Think "4 plus 5 is 9, plus 10 is 19"


Another Example: 14 + 12

Break into Tens and Units: 10 + 4 + 10 + 2

Add the Units: 4 + 2 = 6

Now add on the Tens: 6 + 10 + 10 = 26

Aim for Ten

When a number is close to ten we can "borrow" from the other number so it reaches ten.

Example: 9 + 7

9 is only 1 away from 10

so take 1 from the 7: 9 + 1 + 6
and give it to the 9: 10 + 6 = 16

Think "9 plus 1 is 10 ... 7 less 1 is 6 ... together that is 16"

Example: 8 + 5

8+2=10, so lets take 2 from the 5: 8 + 2 + 3
and give it to the 8: 10 + 3 = 13

We can even move backwards to ten, by making the other number bigger as needed:

Example: 12 + 7

Reduce 12 by 2:  12 − 2 = 10
Increase 7 by 2:  7 + 2 = 9

12 + 7 = 10 + 9 = 19

Compensation Method

"Compensation" is where you round up a number (to make adding easier) and then take away the extra after you have added.

Example 19+16

It is easier to do 20 + 16 = 36

Then take away the extra 1 (that made 19 into 20) to get: 35

Example 395 + 126

It is easier to do 400 + 126 = 526

Then take away the extra 5 (that made 395 into 400) to get: 521

Double when the numbers are the same

Example 5 + 5 = 2 x 5 = 10

Double if the numbers are close, then fix

Example: 5 + 6 is nearly two 5s, but 6 is 1 bigger than 5, so:

5 + 6 = two 5s + 1 = 10 + 1 = 11

Example: 7 + 9 is like two 8s, but 7 is 1 smaller than 8, and 9 is 1 bigger than 8 ... hey! it is exactly two 8s because 1 smaller and 1 bigger cancel each other:

7 + 9 = "8 less 1" + "8 add 1" = two 8s = 16

The Addition Table

We can also use the Addition Table to help us.

 

 
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