Measure using a Centimeter Ruler (cm)
š Meet the Metric System! It's time to learn how the rest of the world measures things. Centimeters are tiny and precise!
Concept
Inches are cool in America, but scientists and almost every other country use the Metric System. šÆ **What is a Centimeter (cm)?** * An inch is pretty big (like your thumb). * A **centimeter** is super tiny! It is about the width of your pinky fingernail, or the width of a little green pea. * There are about two-and-a-half centimeters crammed inside a single inch! šÆ **Measuring with a CM Ruler:** The rules are exactly the same as an inch ruler! 1. **Line it up:** Put the very edge of the object perfectly on the zero line "0". 2. **Read the end:** Look where the object ends. The number it points to is the length in centimeters (cm).
Try it
Read the tiny numbers! **Instructions:** Imagine the object lined up on a centimeter ruler. Start at zero! **Problem 1:** You place a pencil on a cm ruler. It starts at 0, and the tip stops exactly on the 14. * How long is the pencil? ___ cm. **Problem 2:** You place a huge eraser on a cm ruler. It starts at 0, and the edge stops on the 8. * How long is the eraser? ___ cm. **Problem 3:** You put a paperclip on a ruler, but you accidentally start measuring from the "1 cm" mark instead of the "0" mark! It ends perfectly on the 5. * (Uh oh! You have to subtract that extra space you missed!) 5 - 1 = ? * How long is the paperclip? ___ cm.