Math lesson plan · 5th grade (Year 6 in England) · 30 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 · 4 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.
- 1/5 = 5/? → 25Prompt: What was 1 multiplied by to get 5?
- 3/10 − 2/10 = ? → 1/10Prompt: Same denominators: subtract the numerators.
- 2/3 = 8/? → 12Prompt: What was 2 multiplied by to get 8?
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: Add and subtract fractions when one denominator is a multiple of the other. 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: 1/2 + 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 · 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.
- 3/4 + 8/12 = ? → 17/12 (1 5/12)Prompt: Change 3/4 into 12ths.
- 4/5 − 3/15 = ? → 3/5Prompt: Rewrite 4/5 with denominator 15.
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.
- 3/4 + 4/8 = ? → 5/4 (1 1/4)Prompt: Change 3/4 into 8ths.
- 1/5 − 1/15 = ? → 2/15Prompt: Rewrite 1/5 with denominator 15.
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