Math lesson plan · 6th grade (Year 7 in England) · 60 minutes
Multiply mixed numbers
Fractions
CCSS 5.NF.B.6CCSS 6.NS.A.1England: Y6 FractionsEngland: KS3 Number
Objective and success criteria
Students will: Multiply mixed numbers.
- 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: Multiply fractions; Mixed numbers and improper fractions
Leads to: Divide mixed numbers
Materials: Fraction strips or a fraction wall, Paper strips to fold, Number lines, Mini whiteboards and pens, Printed student sheet (below).
Warm-up · 6 min
- Quick retrieval from earlier learning (Multiply fractions; Mixed numbers and improper fractions). Students answer on mini whiteboards.
- Show answers together and note who needs support in the main task.
- Write 3 2/4 as an improper fraction. → 14/4 (3 2/4)Prompt: How many pieces of size 1/4 are in 3 wholes?
- Ines has 28 metres of ribbon and uses 2/4 of it. How many metres is that? → 14Prompt: "Of" means multiply: 2/4 × 28.
- Write 4 3/5 as an improper fraction. → 23/5 (4 3/5)Prompt: How many pieces of size 1/5 are in 4 wholes?
Hook · 6 min
- Cut a pizza or a strip of paper unevenly and ask whether the pieces are really halves or quarters.
- Share the objective: Multiply mixed numbers. Read the success criteria together.
I do: model it · 12 min
- Work through the example out loud, saying why you do each step, not just what you do.
- Example: Work out 3 1/3 × 5. Give a mixed number or fraction in simplest form.
- Step 1: 3 1/3 = 10/3
- Step 2: 10/3 × 5 = 50/3
- Step 3: = 16 2/3
- Answer: 50/3 (16 2/3)
- Pause after each step and ask a student to say what comes next.
We do: guided practice · 12 min
- Do these together. Students try each step on whiteboards before you reveal it.
- Use the hints as prompts rather than giving the answer.
- Work out 3 1/2 × 4. Give a mixed number or fraction in simplest form. → 14Prompt: Write the mixed number as an improper fraction.
- Work out 1 3/4 × 2 3/5. Give a mixed number or fraction in simplest form. → 91/20 (4 11/20)Prompt: Change both mixed numbers to improper fractions.
You do: independent practice · 17 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 · 7 min
- Two questions on their own. Sort answers into got it / nearly / not yet to plan the next lesson.
- Kofi says 3 1/4 × 2 1/2 = 6 1/8, by multiplying the whole numbers and the fractions separately. Find the correct product. → 65/8 (8 1/8)Prompt: Multiplying parts separately misses the cross terms (whole × fraction).
- Work out 2 1/2 × 3. Give a mixed number or fraction in simplest form. → 15/2 (7 1/2)Prompt: Write the mixed number as an improper fraction.
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: Multiply 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
- Move on to: Divide mixed numbers.
- 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