Math lesson plan · 6th grade (Year 7 in England) · 30 minutes
Convert units with ratio reasoning
Measurement
CCSS 6.RP.A.3.DEngland: KS3 Ratio, proportion and rates of changeEngland: KS3 Geometry and measures
Objective and success criteria
Students will: Convert units with ratio reasoning.
- 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: Ratio tables and double number lines; Convert metric units with decimals
Leads to: the next skill in this area.
Materials: Rulers, scales and measuring jugs, Clock faces, Conversion chart, Mini whiteboards and pens, Printed student sheet (below).
Warm-up · 4 min
- Quick retrieval from earlier learning (Ratio tables and double number lines; Convert metric units with decimals). Students answer on mini whiteboards.
- Show answers together and note who needs support in the main task.
- A recipe uses 4 eggs for every 8 pancakes. Complete the table: eggs 4, 8, 20; pancakes 8, 16, __ → 40Prompt: How many times 4 is 20?
- 2569 ml = how many l? → 2.569Prompt: 1 l = 1000 ml.
- A recipe uses 2 eggs for every 4 pancakes. Complete the table: eggs 2, 4, 8; pancakes 4, 8, __ → 16Prompt: How many times 2 is 8?
Hook · 3 min
- Ask the class to estimate the length of the room or the weight of a bag before measuring it.
- Share the objective: Convert units with ratio reasoning. Read the success criteria together.
I do: model it · 7 min
- Work through the example out loud, saying why you do each step, not just what you do.
- Example: 1 kilogram = 1000 grams. How many grams are in 2.5 kilograms?
- Step 1: 2.5 × 1000 = 2500
- Answer: 2500
- Pause after each step and ask a student to say what comes next.
We do: guided practice · 6 min
- Do these together. Students try each step on whiteboards before you reveal it.
- Use the hints as prompts rather than giving the answer.
- 1 hour = 60 minutes. How many minutes are in 0.5 hours? → 30Prompt: Bigger unit → smaller unit: you need more of them, so multiply.
- Convert 950 centimetres to metres. → 9.5Prompt: Smaller unit → bigger unit: you need fewer of them, so divide.
You do: independent practice · 7 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 6 questions are on the student sheet below, with answers in the key.
Exit ticket · 3 min
- Two questions on their own. Sort answers into got it / nearly / not yet to plan the next lesson.
- Convert 300 centimetres to metres. → 3Prompt: Smaller unit → bigger unit: you need fewer of them, so divide.
- A film lasts 140 minutes. How long is that in hours, as a decimal? Round to 2 decimal places if needed. → 2.33Prompt: There are 60 minutes in 1 hour.
Watch out for
- Measuring from the end of the ruler instead of zero.
- Converting units the wrong way (multiplying instead of dividing).
Support and stretch
Support
- Review first: Ratio tables and double number lines.
- Use concrete materials: rulers, scales and measuring jugs.
- 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-6.
Free lesson plan from eurekami.com/lesson-plan-builder