16
You need to add 12.
You need to add 6 - (-9) = 6 + 9 = 15.
You need to add 18 to negative 8 to get 10.
you need to add 10
6
You need to add 7 (or +7)
12
10% of 60 is 6. So, 60 + 6 (10%) = 66
Add 11 -6 + 11 = 5
your expression is this... x + -10 = 2 x = 12 You need a 12 to add to -10 to get 2
Quite easily. Think about what the difference is between the number that you want to subtract and the number that you have. E.g I have the number 10, and I wish to subtract 6 from it: 10-6. To get from 6 to 10, I need to add 4. So in this case, when I minus 6 from 10, I'm left with 4 remaining. So, 10-6=4 Or, let's say I have 16, and I wish to take away 10. To get from 10 to 16, I need to add 6. So whan I minus 10 from 16, I am left with 6 remaining. This means that: 16-10=6 This technique works for subtracting any integer (or any decimal).
-10 + 20 = 10 because you need 10 to get 0 and 10 more to get +10