Question

Bill says that he can add 23 and 40 without regrouping. Is bill correct? How do you know?

Answer 1

He can because you can add it mentally. You can just have 23 in your head and count by adding 10 "4" times. 

Hope this helped☺☺

Answer 2

Yes because 23+40 equals to 63 without any twist or turns, it is a simple answer