Lines of symmetry
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
Use the worked example and teaching sequence below to explain the reasoning before independent practice.
Before You Begin
- Compare matching parts of a shape.
Teaching Steps for Parents and Teachers
- Imagine folding on the proposed line.
- Check whether both halves match exactly.
- Try other directions if asked for all lines of symmetry.
Worked Examples
How many lines of symmetry does a square have?
- A vertical and a horizontal fold each match the halves.
- Each of the two diagonals also matches the halves.
Answer: 4
Common Mistakes and How to Help
A line that divides a shape into equal areas is not necessarily a line of symmetry.
Would every boundary point match after folding?
Questions to Check Understanding
- Would every boundary point match after folding?
- What in the numbers or diagram supports your answer?
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.