Converting within the metric system (from km to mm, for example) is easy, but sometimes it’s still nice to review… since it’s been forever since you had to (America doesn’t use the Metric system very often)! This short video should help refresh your memory!
This gives a couple basic measurement questions for kids ( involving length and perimeter) and a chart of the Metric System. It would be a good whole class activity to create a chart like this (in math journals, on an anchor chart, etc.).