Question

Brandon had to do problems 45 through 75 for homework tonight.
If Brandon did all of the problems he was assigned, how many problems did he do?

Answer 1

45
46
47
48
...
75

Generally speaking just take the last number, subtract the first number, and add 1.

This method only works when you are adding between two numbers inclusively.

(75 - 45) + 1

Answer 2

THANK YOU SO MUCH! God I honestly didn't understand that!

Answer 3

Yeah that's why it's tricky. Usually when we count we start with 1 and go to 10 (or something similar.)

We never stop to realize that if we count from 11 to 21, then that's actually 11 numbers not 10, even though the difference is 10.