What is equal to 15 take away two?
The missing number is at the beginning of the number sentence. And we know this number is equal to 15 take away two. So if we work out 15 take away two, that will tell us the missing number. We can make the number 15 from one ten, which is worth 10, and five ones. And we need to take away two ones, one, two.
We had five ones. We took away two. Three are left. We’re left with one ten and three ones. So 15 take away two equals 13.
13 is equal to 15 take away two.