Question

Craig has a 20 dollar bill.He buys 6 squirt guns for 2 dollars each.How much money did Craig have left?

Answer 1

First you would do 6*2= 12
Then you would subtract 20-12= 8
So Craig has $8 left

Answer 2

he has 20$
when he buy one gun for 2 he'll have 18$ but he wants to buy 6 guns
So the final operation 
20-(2·6)=20-12=8
He'll have 8$ left