Math lesson plan · 4th grade (Year 5 in England) · 45 minutes
Write a fraction in its simplest form
Fractions
CCSS 4.NF.A.1England: Y5 FractionsEngland: Y6 Fractions
Objective and success criteria
Students will: Write a fraction in its simplest form.
- 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: Find the missing number in equivalent fractions; Common factors of two numbers
Leads to: Simplify fractions in one step using the greatest common factor; Convert decimals to fractions in simplest form
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 (Find the missing number in equivalent fractions; Common factors of two numbers). Students answer on mini whiteboards.
- Show answers together and note who needs support in the main task.
- 9/10 = 45/? → 50Prompt: What was 9 multiplied by to get 45?
- Which number is a common factor of 6 and 8? (8 / 3 / 2 / 4) → 2Prompt: A common factor divides both numbers exactly.
- 5/10 = ?/2 → 1Prompt: 10 ÷ ? = 2
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: Write a fraction in its simplest form. 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: Simplify 14/20.
- Step 1: 14 ÷ 2 = 7, 20 ÷ 2 = 10
- Step 2: 7/10
- Answer: 7/10
- 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.
- Simplify 18/48. → 3/8Prompt: Find a number that divides both the top and the bottom.
- Grace says 5/10 is in its simplest form. True or false? (true / false) → falsePrompt: Is there a number other than 1 that divides both 5 and 10?
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.
- 4 out of 20 pupils in a class have a pet. What fraction is that, in its simplest form? → 1/5Prompt: Start with 4/20.
- Simplify 3/12. → 1/4Prompt: Find a number that divides both the top and the bottom.
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: Find the missing number in equivalent 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: Simplify fractions in one step using the greatest common factor; Convert decimals to fractions in simplest form.
- 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-4.
Free lesson plan from eurekami.com/lesson-plan-builder