Question

Each shelf holds 5 hermit-crab cages and 3 hermit-crab care booklets. If there are 23 hermit crab cages and 12 booklets to display, what would you do first to see how many shelves are needed?

Answer 1

1. Each shelf holds 5 hermit-crab cages. There are 23 hermit crab cages to be displayed. Divide the number of hermit crab cages to be displayed by the number of hermit crab cages that can be displayed on each shelf:

$23=5\cdot 4+3.$

This means that you need 5 shelves (4 shelves is not enough, because 3 hermit crab cages will be not displayed).

2. Each shelf holds 3 hermit-crab care booklets. There are 12 hermit-crab care booklets to be displayed. Divide the number of hermit-crab care booklets to be displayed by the number of hermit-crab care booklets that can be displayed on each shelf:

$12=3\cdot 4.$

This means that you need 4 shelves.

Answer: first, you have to divide 23 by 5 and find the quotient and remainder and divide 12 by 3 and find the quotient and remainder. Then you have to determine the number of shelves needed. You need 5 shelves.