Adding
4+0=4
Identity
If n=5, what is n+12
17
n+7=19
n=12
5 x 1 = 5
Identity
If n=9, what is n-3
6
9+n=17
n=8
2+3=3+2
Commutative
If n=7, what is 12-n
5
n=10
4+(5+6)=(4+5)+6
If n=19, what is n+n
38
n-4=5
n=9
9,348+102+5,802
15,252
(2+3)+7=(3+2)+7
Commutative
If n=100, what is n-12
88
15-n=6
n=9