Answer:
one ten was traded for ten ones
Step-by-step explanation:
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
