What is a commutative property of addition mean

The commutative property of addition means that when you see a problem, you change the order. The co in commutative means change order. That's what my teacher told me.

The word "commutative" comes from "commute" or "move around", so the Commutative Property is the one that refers to moving stuff around. For addition, the rule is "a+b=b+a"; in numbers, this means 2+3=3+2. For multiplication, the rule is "ab=ba"; in numbers, this means 2x3=3x2.

You'll have to compass tip on A and draw a small ark with pencil approximately in the middle above AB line, now compass tip to point B and cross the ark you made previously.
Do the same on the opposite side without making any change to the compass 
Join the lines where crosses of arks on the both side meet and then ,it's done.