The question is show how the commutative property of addition works using 2,3,and 5.

Answer 1

It simply means the answer will always be the same no matter what order you put the numbers in!

2+3+5=10
3+2+5=10
5+2+3=10

Answer 2

2 + 3 + 5 = 3 + 5 + 2 = 5 + 3 + 2

Answer 3

http://www.mathematicsdictionary.com/english/vmd/full/c/mutativepropertyofaddition.htm