Math lesson plan · 5th grade (Year 6 in England) · 30 minutes
Multiply a mixed number by a whole number
Fractions
CCSS 5.NF.B.6England: Y6 Fractions
Objective and success criteria
Students will: Multiply a mixed number by a whole number.
- 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 a fraction by a whole number; Mixed numbers and improper 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 · 4 min
- Quick retrieval from earlier learning (Multiply a fraction by a whole number; Mixed numbers and improper fractions). Students answer on mini whiteboards.
- Show answers together and note who needs support in the main task.
- 5 × 1/3 = ? (Give a fraction; it may be improper.) → 5/3 (1 2/3)Prompt: 5 lots of 1/3 is the same as adding it 5 times.
- Write 5 1/3 as an improper fraction. → 16/3 (5 1/3)Prompt: How many pieces of size 1/3 are in 5 wholes?
- Each smoothie uses 1/3 cup of yogurt. Ines makes 7 smoothies. How many cups of yogurt is that? (Simplest form; a whole or mixed number is fine as a fraction.) → 7/3 (2 1/3)Prompt: Multiply the amount for one smoothie by the number of smoothies.
Hook · 3 min
- Cut a pizza or a strip of paper unevenly and ask whether the pieces are really halves or quarters.
- Share the objective: Multiply a mixed number by a whole number. 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: 2 2/5 × 5 = ?
- Step 1: 2 × 5 = 10
- Step 2: 2/5 × 5 = 10/5
- Step 3: 10 + 10/5 = 12
- Answer: 12
- 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.
- 4 1/2 × 2 = ? → 9Prompt: Multiply the whole part: 4 × 2.
- Each bag of compost weighs 3 1/2 kg. How much do 5 bags weigh? → 35/2 (17 1/2)Prompt: Work out 5 × 3 1/2.
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.
- 2 1/4 × 4 = ? → 9Prompt: Multiply the whole part: 2 × 4.
- Each bag of compost weighs 2 1/2 kg. How much do 3 bags weigh? → 15/2 (7 1/2)Prompt: Work out 3 × 2 1/2.
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 a fraction by a whole number.
- 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-5.
Free lesson plan from eurekami.com/lesson-plan-builder