3rd Grade Metric Units of Length Worksheet

Before reading the two choices, ask your child to picture the object or the trip. Then they can show its size with their fingers or their arms. A toothpick fits between two fingers, so 6 centimeters is sensible, whereas 6 millimeters is barely the width of a pencil. In the same way, a grown-up is about 170 centimeters tall, because 170 meters would be taller than a building.

After that, saying the size out loud helps your child reject the estimate that does not fit.

Next, line the metric units up from small to large: millimeter, centimeter, meter, kilometer. Ten millimeters make one centimeter, and one hundred centimeters make one meter. Likewise, one thousand meters make one kilometer. So a dessert spoon is about 19 centimeters long, while the road from Dallas to Houston is about 385 kilometers.

Millimeters and kilometers come back in 4th grade, so this page is a gentle first meeting with them.

To begin, compare the five answers with the answer key on page two. Then take a ruler marked in centimeters and measure a spoon, a fork and a toothpick together. Ask your child to estimate each length first, and only then to check it. Finally, look at a road sign or a map app, because distances between cities are given in kilometers in most countries.