Question

What number replaces the ∆?

5 = 5
5 + 2 = 5 + ∆

Answer 1

Well, do you know what property this is showing?

Answer 2

Actually, we should start with, do you know your math properties?

Answer 3

This is showing commutative property. That means it doesn't matter what order the numbers are written in.
ex. a+b=b+a or 1+2=2+1

Answer 4

That should help you figure out what number replaces the ∆ :)

Answer 5

:)

Answer 6

You figure it out? :P