Math lesson plan · 7th grade (Year 8 in England) · 45 minutes
Markup, profit and commission
Decimals and percentages
CCSS 7.RP.A.3England: KS3 NumberEngland: GCSE Foundation Ratio
Objective and success criteria
Students will: Markup, profit and commission.
- I can answer questions on today's skill on my own, without help.
- I can explain each step and say why it works.
- I can check my answer and spot a mistake.
Before and after
Needs first: Increase an amount by a percentage
Leads to: the next skill in this area.
Materials: Place value chart with tenths and hundredths, Hundred squares, Number lines, Mini whiteboards and pens, Printed student sheet (below).
Warm-up · 5 min
- Quick retrieval from earlier learning (Increase an amount by a percentage). Students answer on mini whiteboards.
- Show answers together and note who needs support in the main task.
- Increase 360 by 30%. → 468Prompt: Find 30% of 360.
- A video had 2100 views. Views went up by 12% the next day. How many views did it have then? → 2352Prompt: Increasing by 12% means you end up with 112%.
- Kofi increases 200 by 10% and then decreases the answer by 10%. Kofi expects to get back to 200. What does Kofi actually get? → 198Prompt: The second percentage is of a different (bigger) amount.
Hook · 5 min
- Show two prices or race times with decimals and ask which is bigger, then why.
- Share the objective: Markup, profit and commission. Read the success criteria together.
I do: model it · 10 min
- Work through the example out loud, saying why you do each step, not just what you do.
- Example: A shop buys a T-shirt for $30 and marks it up by 40%. What is the selling price? (Type the number only.)
- Step 1: 40% × 30 = 12
- Step 2: 30 + 12 = 42
- Answer: 42
- Pause after each step and ask a student to say what comes next.
We do: guided practice · 10 min
- Do these together. Students try each step on whiteboards before you reveal it.
- Use the hints as prompts rather than giving the answer.
- A shop buys a T-shirt for $4 and marks it up by 25%. What is the selling price? (Type the number only.) → 5Prompt: The markup is a percentage of the cost price.
- A bakery's cost for a cake is $108 and it sells it for $118.80. What is the percentage markup (profit as a percentage of cost)? → 10Prompt: Profit = selling price − cost.
You do: independent practice · 10 min
- Students work on the student sheet. Circulate and check the first two answers of every student early.
- Students who finish: write a question of their own for a partner, with the answer.
The 8 questions are on the student sheet below, with answers in the key.
Exit ticket · 5 min
- Two questions on their own. Sort answers into got it / nearly / not yet to plan the next lesson.
- Mei sells solar panels and earns 5% commission on sales. This month Mei sold $3200 worth. How much commission is that? (Type the number only.) → 160Prompt: Commission is a percentage of the sales.
- A shop buys a T-shirt for $18 and marks it up by 40%. What is the selling price? (Type the number only.) → 25.2Prompt: The markup is a percentage of the cost price.
Watch out for
- Thinking 0.45 is bigger than 0.5 because 45 is bigger than 5.
- Moving the digits the wrong way when multiplying or dividing by 10.
Support and stretch
Support
- Review first: Increase an amount by a percentage.
- Use concrete materials: place value chart with tenths and hundredths.
- Give the first step of each question, or a partly worked example to finish.
- Pair with a confident partner for the guided practice.
Stretch
- Explain a common mistake in writing and how to fix it.
- Write a word problem that uses today's skill, then solve a partner's.
Homework and more practice
Free online practice with hints and printable worksheets for this skill: eurekami.com/math/grade-7.
Free lesson plan from eurekami.com/lesson-plan-builder