Third grade students aren’t expected to solve complicated multiplication problems, but they should be able to multiply by ten. This is all it takes to understand the metric system. Since the metric system is based on powers of ten, students need to be able to multiply by ten and multiples of ten to understand the relationships between different metric units. Students can be familiarized with multiplying by multiples of ten before even being introduced to metric units.
Unlike the American system of measurement, the metric system is built on a few basic units of measure. Where in the American system of measurement, students have to know inches, feet, yards and miles, the only unit of students need to measure length in the metric system is the meter. Teach students the basic metric units, such as meter and liter, and then students only need to learn the prefixes which apply to all units of metric measure in the same way. For instance, “centi” means “one hundredth, whether it is applied to meters or liters.
Students need to learn the concepts and reasoning behind the metric system, but they are going to need to develop some practical experience to really understand how the metric system works. Third grade students will learn much more from engaging, relevant learning activities than listening to a teacher. Give them rules and have them measure desks. Let them use meter sticks to measure the classroom and have them fill containers with liters of water.
Make the lessons personal. Have students measure and weigh themselves. Third grade students will be more engaged in lessons that connect to them personally. They will also get to use the metric system in more practical applications.