Your answer would be:
596.64 = 596.640
Reasoning= If you just take away the zero from 596.640 you would have the same answer as 596.64. Now if you add a zero to 596.64 you still would have the same answer, therefore they are equal.
Hope this helps! (:
15 round by the nearest 10 is 20.
8 ounces, it said it at the end of the question.
I don't think you can because the variables are different. You can only add the same variables.
