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

Subtract a Multiple of 100 from a 3-Digit Number

🦘 Giant leaps backward! What happens when you subtract an easy number like 400 from a messy number like 832?

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

Lesson 125 of 186

Concept

Subtracting perfect hundreds is the easiest subtraction skill.

🎯 The "Hundreds Only" Shortcut: Example: 749 - 300 = ? Look at the zeros. The 0 in the Tens place means the 4 is completely safe! The 0 in the Ones place means the 9 is completely safe!

1. Freeze the Tens and Ones (the "49" is frozen). 2. Subtract the Hundreds! 7 - 3 = 4. 3. Turn the frozen pieces back on. 4. Answer: 449!

You just solved a giant math problem by just thinking "7 - 3".

Try it

Spin the dial backward!

Instructions: The Tens and Ones digits are frozen in ice. You can only destroy the Hundreds digit!

Problem 1: 852 - 400 = ? * Tens and Ones: "52". (Frozen!) * Hundreds: 8 - 4 = ___ * Answer: ___

Problem 2: 619 - 200 = ? * Answer: ___

Problem 3: 593 - 500 = ? * (Hint: 5 - 5 = 0. The Hundreds digit is gone entirely!) * Answer: ___

Problem 4: 924 - 100 = ? * Answer: ___