2. Total ÷ Each copy = 4 copies.
3. Total number of copies = each copy.
4, multiple × multiple = multiple.
5, several multiples ÷ multiples = multiples.
6. Several times/multiple = multiple.
7. Speed × time = distance.
8. Distance/speed = time.
9. Distance ÷ time = speed.
10, unit price × quantity = total price.
1 1, total price/unit price = quantity.
12, total price ÷ quantity = unit price.
13, working efficiency × working time = total workload.
14, total workload ÷ working efficiency = working time.