Worksheet Library / Number Sense
Break Apart a Number in Different Ways
Focus: Decomposing Numbers Within 5. Use the worked example and teaching sequence below to explain the reasoning before independent practice.
Use New Numbers to make another set. Choose Worksheet or Answer Key, then use the worksheet’s Print button.
Teaching Notes
Focus: Decomposing Numbers Within 5. Use the worked example and teaching sequence below to explain the reasoning before independent practice.
Before You Begin
- Count a whole set and its parts.
Teaching Steps for Parents and Teachers
- Identify the whole and the two parts.
- Add the parts to find the whole.
- Subtract a known part from the whole to find a missing part.
Worked Examples
A set has 5 objects. 2 are in one group. How many are in the other group?
- 5 − 2 = 3.
- Check the two parts: 2 + 3 = 5.
Answer: 3
Common Mistakes and How to Help
A part cannot be counted twice in the whole.
Show how the two parts make the original whole.
Questions to Check Understanding
- Show how the two parts make the original whole.
- 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.