Math lesson plan · 5th grade (Year 6 in England) · 45 minutes
Add and subtract fractions when one denominator is a multiple of the other
Fractions
CCSS 5.NF.A.1England: Y5 Fractions
Objective and success criteria
Students will: Add and subtract fractions when one denominator is a multiple of the other.
- 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: Add and subtract fractions with like denominators; Find the missing number in equivalent 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 (Add and subtract fractions with like denominators; Find the missing number in equivalent fractions). Students answer on mini whiteboards.
- Show answers together and note who needs support in the main task.
- 3/10 = ?/60 → 18Prompt: What was 10 multiplied by to get 60?
- 4/9 − 3/9 = ? → 1/9Prompt: Same denominators: subtract the numerators.
- 1/2 = ?/4 → 2Prompt: What was 2 multiplied by to get 4?
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: Add and subtract fractions when one denominator is a multiple of the other. 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: 1/2 + 5/8 = ?
- Step 1: 1/2 = 4/8
- Step 2: 4/8 + 5/8 = 9/8
- Step 3: 1 1/8
- Answer: 9/8 (1 1/8)
- 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.
- 2/3 + 7/9 = ? → 13/9 (1 4/9)Prompt: Change 2/3 into 9ths.
- 1/2 − 1/8 = ? → 3/8Prompt: Rewrite 1/2 with denominator 8.
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.
- 2/3 + 3/9 = ? → 1Prompt: Change 2/3 into 9ths.
- 1/3 − 2/9 = ? → 1/9Prompt: Rewrite 1/3 with denominator 9.
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: Add and subtract fractions with like denominators.
- 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