The difference is referring to subtraction, so the question was most likely something like how much longer is this butterflies wings than this ones. so 4.55 might be one of the lengths and 3 might be the other, so 4.55 - 3 is 1.55.
There are 120 blocks left.
490 divided by 35 equals 14. It would take Jack 14 minutes to write a 490 word essay.
