Find the Endpoint on a Number Line

Teaching Notes

Focus: Counting Back with a Number Line. Use the worked example and teaching sequence below to explain the reasoning before independent practice.

Before You Begin

• Count backward from any starting number.

Teaching Steps for Parents and Teachers

1. Start at the number being subtracted from.
2. Move backward one step for each unit removed.
3. The landing number is the difference.

Worked Examples

9 − 3 = □

1. Start at 9.
2. Take three backward steps: 8, 7, 6.

Answer: 6

Common Mistakes and How to Help

Count moves rather than including the starting number.

Add the removed amount to the result to check: 6 + 3 = 9.

Questions to Check Understanding

• Add the removed amount to the result to check: 6 + 3 = 9.
• Which step explains your answer?
• Can you apply the same reasoning when the numbers change?

Practice Advice

Work through the example together. Ask the learner to explain the first two problems, then try three independently. Review the first incorrect step before assigning more practice.

Next Practice

• Use New Numbers to practice the same skill with different values.
• If the learner needs help, return to the example and model each step before trying again.