2
2Keywords:
addition
additive identity
commutativity
inverse
properties of zero
subtraction
Students use the additive identity and the commutative property to assist them to solve simple equations without calculating.
2
0
1
2
2
7
6
4
2
1
3
0
1
2
3
1
1
3
1
1
1
5
1
4
5
