K-5 friendly lesson
One small step at a time.Read the idea, try the activity, and celebrate each win as you go.
Use number lines to subtract three-digit numbers
🚀 3-2-1... blast off backward! We can use an open number line to count back by hundreds and tens to solve huge subtraction problems.
Do this: Read the concept below, then try the quiz or activity.
Lesson 8 of 220
Concept
When you subtract on a number line, you start on the right side and jump backward to the left!
🎯 How to Subtract on a Number Line: Example: 468 - 215 = ? 1. Start with the big number on the right side of the line: 468. 2. Break apart the part you are subtracting (215). It has 2 hundreds, 1 ten, and 5 ones. 3. Jump Backward: - HUNDREDS: Jump back 200 from 468. You land at 268. - TENS: Jump back 10 from 268. You land at 258. - ONES: Jump back 5 from 258. You land at 253. 4. Your final landing spot is the answer! So, 468 - 215 = 253.
Try it
Do you have your backward rocket boosters ready?
Instructions: Mentally jump backward on the number line to find the difference.
Problem 1: 500 - 200 * Start at 500. Take 2 huge hundred jumps backward. * Answer: ___
Problem 2: 380 - 150 * Start at 380. Jump back 100, then jump back 50. * Answer: ___
Problem 3: 725 - 110 * Start at 725. Jump back 100, then jump back 10. * Answer: ___
Problem 4: 899 - 400 * Answer: ___