Adding Strategies
Contents
Strategies can help with recall of addition facts
The Nines Trick
Any number plus 9, is one less than the digit in the ones column plus 10
See how this works in the following examples:
8+9=17 - one less than 8 is 7 plus 10 more equals 17
15+9=24 - one less than 5 is 4 plus 10 more with the tens is 24
Make a Ten
Make ten and then add the remaining amount.
For example: 8+6 You think oh I know 8 and 2 more make ten. I will take 2 from the 6 to make ten and I have 4 left over so 10 + 4 = 14. therefore 8+6 = 14
Doubles
Learning the doubles is like counting by twos. 1+1 is 2, 2+2 is 4, 3+3 is 6, 4+4 is 8, 5+5 is 10 and so on.
Nearly Doubles
Once you know the doubles, you can expand that knowledge to doubles plus or minus one.
For example, if you know 6+6 is 12 then you can know that 6 +7 is 12 +1 which is 13.
Another examples is 7+8 I know 7+7 is 14 so 7+8 is 14 +1 which = 15
It can also be the opposite, such as 8+9 I know 9 +9 is 18 so 8+9 = 18-1=17
