Adding and taking away within 18 · Usually met around P1
Doubles
Know every double without thinking.
How to do it
Method
Know every double without thinking
6 + 6 = 12, 7 + 7 = 14, 8 + 8 = 16
Another way
Make ten
7 + 7 = 7 + 3 + 4 = 10 + 4 = 14
In full
Know your doubles as well as your own phone number: 6+6=12, 7+7=14, 8+8=16, 9+9=18. Once you know them by heart, you can use them to work out lots of other facts.
Worked examples
Have a go first, then open each one for the answer and the working.
Example 1
4 + 4
Show the answer and working
Answer: 4 + 4 = 8
double 4, 4 + 4 = 8
Example 2
2 + 2
Show the answer and working
Answer: 2 + 2 = 4
double 2, 2 + 2 = 4
Example 3
3 + 3
Show the answer and working
Answer: 3 + 3 = 6
double 3, 3 + 3 = 6
Practise it in the game →Adding and taking away within 18 · Free to start, unlimited questions, no download