372 cannot be divided by 3 easily. However, 360 +12 can be divided by 3 easily, so it makes sense to trade one of the seven tens for ten ones. That will leave 6 tens, but give twelve ones.
370 +2 = 360 +12 . . . . where the "+" numbers are the numbers of ones
The tay would move to the left because that is a less than sign . positive goes to the right and negative goes to the left . thing of the less sign like a L bc it looks like one .