K-5 friendly lesson
One small step at a time.Read the idea, try the activity, and celebrate each win as you go.

Compare Lengths in Centimeters (cm)

πŸ”¬ Tiny comparisons! It's time to compare two objects using centimeter numbers. Do you remember the trick for "comparing"?

Do this: Read the concept below, then try the quiz or activity.

Lesson 89 of 186

Concept

Comparing means finding the difference. And "difference" means subtraction!

🎯 The "Centimeter Difference" Strategy: Example: A green caterpillar is 14 centimeters long. A yellow caterpillar is 8 centimeters long. How much longer is the green one?

1. Find the Action: "How much longer?" means Compare. Compare means subtract! 2. Setup the Math: Big number minus Small number. (14 - 8). 3. Solve it! Use your single-digit ninja counting tricks! (Take 4 to get to 10. Take 4 more. Answer is 6!) 4. Answer: The green caterpillar is 6 cm longer.

Centimeters are tiny numbers, so the answers you get will seem a lot bigger than they would if you used inches!

Try it

Find the metric difference!

Instructions: Read the two measurements in centimeters and subtract to find the difference.

Problem 1: The blue chalk is 12 cm long. The yellow chalk is 5 cm long. * How much longer is the blue chalk? (12 - 5 = ___) * Answer: ___ cm.

Problem 2: Your new pencil is 18 cm long. Your old, sharpened pencil is 9 cm long. * How much shorter is the old pencil? (___ - ___) * Answer: ___ cm.

Problem 3: A leaf is 22 cm wide. A beetle on the leaf is 3 cm wide. * What is the difference in their width? * Answer: ___ cm.

Problem 4: A big paint brush is 28 cm. A small brush is 15 cm. How much longer is the big brush? * Answer: ___ cm.