How the metric system is superior…
There is a powerful advantage of the metric length units. The centimeter is subdivided into only one unit, the millimeter. Ten millimeters make one centimeter. Now compare that simplicity with the division of the inch. There’s half an inch, one quarter of an inch, an eighth of an inch, and a sixteenth of an inch. Adding fractions of an inch requires converting to a common denominator, such as eighths of sixteenths. It’s a lot of work. Students will need to work with both systems, but working in metric does have its advantages. You could create other math problems involving the metric system in calculating cost to give students extra problem-solving practice.