Lesson Plan

• Describe the difference between permutations and combinations and identify appropriate contexts.
• Apply factorial notation to compute permutations and combinations.
• Solve arrangement and selection problems using the correct formula.
• Analyse word problems to decide whether order matters.
• Check solutions for common errors such as missing factorial terms.

• Projector and screen
• Whiteboard and markers
• Printed worksheet with practice questions
• Scientific calculators
• Formula reference sheet (permutations & combinations)
• Student notebooks

Begin with a quick real‑life scenario: arranging seats for the school concert. Review the factorial notation learned previously. Explain that by the end of the lesson students will be able to decide which formula to use and compute the answer correctly.

1. Do‑now (5'): Warm‑up – number of ways to arrange 3 books on a shelf; recall factorial.
2. Mini‑lecture (10'): Define permutations vs. combinations, highlight keywords, display formulas on the projector.
3. Guided Example 1 – Permutation (12'): Choir line‑up problem; step‑by‑step modelling and class checks.
4. Guided Example 2 – Combination (12'): Forming a group of 4 from 12 students; identify order‑irrelevant, calculate.
5. Independent Practice (15'): Students attempt three worksheet questions; teacher circulates for support.
6. Check for Understanding (6'): Exit‑ticket – one short problem where students state the correct formula and answer.

Summarise the key distinction between permutations and combinations and the importance of keywords. Collect exit‑tickets to gauge understanding, and assign the remaining worksheet questions as homework for reinforcement.