1. 15
2.16
3.60
Challenge is 40!
How we know 5 plus 5 equals 10 plus another 5 equals 15!
if you put 2 8’s together you can get 16!
if you times 6 by ten it adds a 0 at the end leaving you with 60
last one 10 plus 10 plus 10 plus 10 equals 40 which is equivalent to 8 times 5!