Math lesson plan · 6th grade (Year 7 in England) · 45 minutes
Reason about fraction division: method and size of the answer
Fractions
CCSS 6.NS.A.1England: KS3 Number
Objective and success criteria
Students will: Reason about fraction division: method and size of the answer.
- 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: Divide fractions by fractions
Leads to: the next skill in this area.
Materials: Fraction strips or a fraction wall, Paper strips to fold, Number lines, Mini whiteboards and pens, Printed student sheet (below).
Warm-up · 5 min
- Quick retrieval from earlier learning (Divide fractions by fractions). Students answer on mini whiteboards.
- Show answers together and note who needs support in the main task.
- 5/6 ÷ 1/2 = ? Give your answer in simplest form. → 5/3 (1 2/3)Prompt: Dividing by a fraction is the same as multiplying by its reciprocal.
- Ines has 8 cups of flour. Each batch of pancakes needs 2/8 cup. How many batches can Ines make? → 32Prompt: How many groups of the batch size fit into the total? That is division.
- 3 2/3 ÷ 1/2 = ? (Simplest form; an improper fraction is fine.) → 22/3 (7 1/3)Prompt: Change the mixed number into an improper fraction first.
Hook · 5 min
- Cut a pizza or a strip of paper unevenly and ask whether the pieces are really halves or quarters.
- Share the objective: Reason about fraction division: method and size of the answer. 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: Which calculation gives the same answer as 1/4 ÷ 4/9?
- Step 1: 1/4 ÷ 4/9 = 1/4 × 9/4
- Answer: 1/4 × 9/4
- 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.
- Which calculation gives the same answer as 1/2 ÷ 1/3? (1/2 × 3/1 / 2/1 × 3/1 / 2/1 × 1/3 / 1/2 × 1/3) → 1/2 × 3/1Prompt: Keep the first fraction as it is.
- Without calculating: is 12 ÷ 1/8 greater than or less than 12? (Greater than 12 / Less than 12) → Greater than 12Prompt: Is the divisor less than 1 or greater than 1?
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.
- Kwame worked out 1/8 ÷ 1/2 by flipping the first fraction: 8/1 × 1/2. What is the correct answer? Give a fraction in simplest form. → 1/4Prompt: Which fraction should be flipped?
- Without calculating: is 3 ÷ 2/3 greater than or less than 3? (Greater than 3 / Less than 3) → Greater than 3Prompt: Is the divisor less than 1 or greater than 1?
Watch out for
- Thinking a bigger denominator means a bigger fraction (1/8 > 1/4).
- Adding the denominators when adding fractions (1/2 + 1/3 = 2/5).
Support and stretch
Support
- Review first: Divide fractions by fractions.
- Use concrete materials: fraction strips or a fraction wall.
- 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