Subtracting Fractions Review

Overview

This is lesson 7 of 10 in Understanding Fractions Together. Students review subtracting fractions with like denominators using visual models, concrete materials, an interactive game and a differentiated worksheet. The lesson is designed for 11 students aged 12–14 who are working broadly within Year 2–4 mathematics expectations.

Learning intentions

• WALT subtract fractions with like denominators.
• Students will recognise that the denominator names the equal parts and stays the same.
• Students will subtract the numerators and check their answer using a model.
• Students will explain their strategy using pictures, words or numbers.

Success criteria

• I can identify the numerator and denominator.
• I can keep the denominator the same when subtracting like fractions.
• I can subtract the numerators accurately.
• I can show or explain how I know my answer is correct.

Curriculum links

• Representing and interpreting unit fractions and fractions with equal parts.
• Using concrete materials, visual representations and number sentences to solve problems.
• Applying addition and subtraction strategies to solve mathematical problems.
• Communicating mathematical reasoning using drawings, materials, words and symbols.

Lesson structure (45 minutes)

1. 0–5 minutes – Welcome and retrieval hook

Open with the fraction subtraction hook and learning intention. Display a picture of a chocolate bar divided into equal parts, with some parts being removed. Ask: “If I have 5 sixths and take away 2 sixths, how many sixths are left?” Students make a quick prediction using fingers, mini-whiteboards or spoken responses.

Revisit the WALT and success criteria in accessible language. Explain that today’s focus is subtracting fractions with the same denominator.

2. 5–12 minutes – Explicit teaching and modelling

Use the worked examples and visual models to model a subtraction such as (5/6 - 2/6). Build 5 sixths with fraction pieces, remove 2 sixths, and count the 3 sixths remaining. Record:

(5/6 - 2/6 = 3/6)

Emphasise: “The denominator stays the same because the size of the pieces has not changed. We subtract the numerators because we are taking away pieces.” Also model (4/5 - 1/5) and connect the concrete model to the number sentence.

3. 12–20 minutes – Guided concrete practice

In pairs, students use the fraction circles cut-out pack to build and solve subtraction examples shown on the guided practice questions. Begin with halves, thirds and quarters before moving to fifths, sixths or eighths where appropriate.

For each example, students should:

• Build the first fraction.
• Remove the second fraction.
• Count what remains.
• Say the matching number sentence.

Circulate and ask: “What does the denominator tell us?” and “Why did the denominator stay the same?”

4. 20–30 minutes – Interactive subtraction game

Display the subtraction game instructions and question cards. Students work in three groups: two pairs and one group of three. Each student takes a turn choosing a displayed problem, modelling it with fraction circles if needed, and explaining the answer. Award a point for a correct answer and an additional point for a clear explanation or model.

Use examples such as (3/4 - 1/4), (6/8 - 2/8), (7/10 - 3/10) and (5/6 - 4/6). Adjust the denominator and size of the numerator according to student readiness. Pause halfway for a quick whole-class check.

5. 30–40 minutes – Differentiated worksheet practice

Distribute the differentiated fraction subtraction worksheet. Students complete the section that matches their current level.

• Support: picture-based questions with halves, thirds and quarters; students colour or cross out parts before writing the answer.
• Core: subtract fractions with like denominators and complete missing-numerator questions.
• Challenge: solve short word problems and explain why the denominator remains unchanged.

Encourage students to use the fraction circles or draw bars. Work closely with students who need one-to-one prompting, reading support or help recording numerals.

6. 40–45 minutes – Review and exit check

Return to the discussion prompts and plenary. Ask students to complete and explain the sentence: “When subtracting fractions with like denominators, I subtract the ______ and keep the ______ the same.”

Give each student one final question, such as (5/8 - 3/8). Students may answer with a drawing, fraction circles, a number sentence or an oral explanation. Briefly celebrate progress and preview that the next lesson will apply fraction subtraction in problem-solving situations.

Resources

• the fraction subtraction lesson slide deck
• the differentiated fraction subtraction worksheet
• the fraction circles cut-out pack
• Mini-whiteboards, markers and erasers
• Scissors and folders or envelopes for storing fraction circles
• Counters or small classroom objects for additional modelling
• Pencils and coloured pencils
• Visual timer
• Optional vocabulary display: numerator, denominator, subtract, equal parts

Assessment

• Observe whether students build the first fraction accurately, remove the correct number of parts and retain the denominator.
• Listen for explanations that distinguish the numerator from the denominator.
• Use the worksheet and final question to identify students who can calculate independently, those who need visual support and those ready for word problems.

Differentiation

• Use concrete fraction circles, large visual models, repeated language and worked examples for students requiring substantial support.
• Reduce the number of questions and use familiar denominators such as 2, 3 and 4 before introducing sixths, eighths or tenths.
• Provide sentence frames such as “I had ___ parts, took away ___ parts, so ___ parts are left.”
• Offer challenge through missing-number equations, comparisons of answers and simple real-life problems; provide oral instructions, partner reading, enlarged print and additional processing time for EAL learners and students with learning needs.