Ok, I'll make it simple for you: Keep Change Change. For all subtraction problems (and only subtraction, no addition), all you have to do is keep the first number, then change the sign from a minus to a plus, and then change the last number to the opposite. For example:
7 - (-3)
7 + 3=10
-4 - 10
-4 + -10= -14
For addition, if both numbers are negative, you just add them together. For example:
-21 + (-13)= -34
In this case you switch the sign and the number's sign also:
7 + (-18)
7 - 18 = -11
I hope I was help!!!
