Give an example of an addition problem in which you would and would not group the addends differently to add

If you're adding positive numbers together, then the order in which you write or group the addends doesn't matter.

If you're "adding" a negative number to a positive number, it's a little easier to visualize this problem if you write the positive number first, followed by the negative number.

But if you're "adding" -15 to 8, it'd make sense to write the -15 first (because its magnitude is greater) and then the 8:  -15 + 8 = -7

The answer for this question is 80