Math lesson plan · 6th grade (Year 7 in England) · 45 minutes
Work out unit prices
Ratio and proportion
CCSS 6.RP.A.2CCSS 6.RP.A.3.BEngland: KS3 Ratio, proportion and rates of changeEngland: GCSE Foundation Ratio
Objective and success criteria
Students will: Work out unit prices.
- 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: Unit rates; Divide decimals
Leads to: Compare deals to find the better value
Materials: Bar models, Double number lines, Ratio tables, Mini whiteboards and pens, Printed student sheet (below).
Warm-up · 5 min
- Quick retrieval from earlier learning (Unit rates; Divide decimals). Students answer on mini whiteboards.
- Show answers together and note who needs support in the main task.
- 3 notebooks cost $12. What is the cost of one notebook? (Type the number only.) → 4Prompt: A unit rate is the amount for ONE.
- 17.4 ÷ 2 = ? → 8.7Prompt: Divide as with whole numbers.
- Hiro travels 90 miles in 3 hours at a steady speed. How far does Hiro travel in one hour? → 30Prompt: Find the distance for one hour.
Hook · 5 min
- Share a recipe for 4 people and ask how much is needed for 6.
- Share the objective: Work out unit prices. 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: 4 notebooks cost $3.16. What is the price for 1? (Type the number only.)
- Step 1: 3.16 ÷ 4 = 0.79
- Answer: 0.79
- 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.
- 5 kg of oranges cost $20.45. What is the price for 1? (Type the number only.) → 4.09Prompt: Unit price = total cost ÷ number of items.
- A 300 g bag of pasta costs $1.68. What is the cost per 100 g? (Type the number only.) → 0.56Prompt: How many lots of 100 g are in 300 g?
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.
- 4 smoothies cost $8.64. At the same price each, how much do 8 smoothies cost? (Type the number only.) → 17.28Prompt: Find the price of one smoothie first.
- 4 litres of milk cost $16.68. What is the price for 1? (Type the number only.) → 4.17Prompt: Unit price = total cost ÷ number of items.
Watch out for
- Adding the same amount to both parts instead of multiplying.
- Mixing up part-to-part and part-to-whole ratios.
Support and stretch
Support
- Review first: Unit rates.
- Use concrete materials: bar models.
- Give the first step of each question, or a partly worked example to finish.
- Pair with a confident partner for the guided practice.
Stretch
- Move on to: Compare deals to find the better value.
- 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-6.
Free lesson plan from eurekami.com/lesson-plan-builder