11 Plus Maths Fractions: A Complete Revision Guide

Why Fractions Matter So Much in the 11 Plus

In a standard GL Assessment maths paper of 50–60 questions, you can expect roughly 8–12 questions that directly test fractions. But the real number is higher. Fractions underpin a wide range of related topics:

• Percentages — converting a percentage to a fraction is often the fastest route to the answer
• Ratio and proportion — equivalent fractions are the foundation of ratio simplification
• Decimals — converting between fractions and decimals appears in multiple question types
• Word problems — multi-step problems frequently involve finding a fraction of a quantity

A child who is confident with fractions gains a significant advantage. A child who is shaky on them doesn’t just drop marks on fraction questions — they slow down across the entire paper.

The 8 Fraction Topics Your Child Must Know

The 11 Plus doesn’t test fractions in a single way. There are eight distinct skill areas your child needs to be comfortable with. Start with the first four in Year 4–5; work through all eight before Year 6 practice papers begin.

How GL and CEM Test Fractions Differently

Both exam boards test the same fraction topics, but the style, format, and difficulty of questions varies meaningfully. Understanding the difference helps you focus your child’s revision on the right thing.

Which board does your school use?

Most grammar schools in England use GL Assessment. CEM is used by a smaller number of authorities, including parts of Birmingham and Wiltshire. Your school’s website or local council will confirm which board they use. If you’re not sure, prepare for GL — GL-style fraction practice is transferable to CEM, but not always the other way round.

The 5 Most Common Fractions Mistakes in the 11 Plus

These are the errors that appear most frequently in children’s practice papers. Go through each one with your child — recognising the mistake pattern is half the fix.

• Adding numerators and denominators separately. The classic error: 1/2 + 1/3 = 2/5. This is wrong. To add fractions, you must first find a common denominator. The correct answer is 5/6. This mistake appears because the “shortcut” looks intuitive but is mathematically incorrect. Drilling the common-denominator process until it’s automatic eliminates this.
• Forgetting to simplify the final answer. A child calculates 6/8 and moves on. The correct answer is 3/4. Many marking schemes award zero for unsimplified fractions. Teach your child to always check: can the numerator and denominator be divided by the same number? Make simplifying the final step as automatic as checking their working.
• Errors when converting mixed numbers to improper fractions. Converting 3⅖ to an improper fraction requires multiplying the whole number by the denominator and adding the numerator: (3 × 5) + 2 = 17, so the answer is 17/5. A common error is adding the whole number to the numerator instead (giving 5/5 or similar). This mistake becomes more frequent under time pressure.
• Using the wrong common denominator. When children rush, they sometimes use a common denominator that isn’t the lowest common denominator, which leads to larger numbers and more arithmetic errors. For example, when adding 1/4 + 1/6, some children use 24 instead of 12, multiplying correctly but increasing the chance of an arithmetic slip. Practice with the lowest common denominator reduces errors under time pressure.
• Misreading “fraction of an amount” questions. When asked to find 3/5 of 40, a child must divide by the denominator first (40 ÷ 5 = 8) then multiply by the numerator (8 × 3 = 24). Many children multiply first, which leads to unwieldy numbers. In a word problem context, they also sometimes find 1/5 and forget to multiply by 3. The fix: write out both steps explicitly before calculating.

Practice Tips for Parents and Tutors

Fractions respond well to methodical practice. Here’s how to structure sessions that build lasting accuracy, not just short-term familiarity.

Build the foundations first

Children who struggle with fractions in Year 5 usually have a gap in one of the basics: they don’t fully understand what a fraction represents, or they can’t find a common factor quickly. Spend time on visual fraction models (bar models and pie charts) before moving to abstract calculation. A child who understands why 1/2 equals 2/4 makes far fewer errors than one who has memorised the process.

Use the “two-step” drill for adding and subtracting

Make the two steps automatic through repetition. Step 1: find the common denominator and convert both fractions. Step 2: add or subtract the numerators. Do not skip to a combined approach until each step is reliable in isolation. Ten focused questions per session — with immediate self-checking — is more effective than 50 questions marked at the end.

Time your child from Year 5 onwards

The 11 Plus is as much a test of speed as accuracy. Once your child can solve a fraction question correctly, start timing. The target for a standalone fraction question in the GL paper is under 50 seconds. If they’re regularly taking 90 seconds or more, accuracy under the time constraint will suffer on exam day.

Use exam-standard questions, not textbook questions

Textbook fractions are structured to teach a concept. 11 Plus fractions questions are structured to test it under time pressure, often with deliberate distractors in the multiple choice answers. Practising from 11 Plus-specific fractions worksheets gives your child familiarity with the question style and the traps setters use.

Fractions are just one part of the 11 Plus maths paper. For a complete picture of every topic tested — and how to prioritise them — see our full 11 Plus maths topics guide.

Review every wrong answer — not just the score

The score tells you how well your child did. The mistakes tell you what to fix. When reviewing a practice paper, don’t just mark right and wrong — ask your child to talk through their working for each incorrect answer. The error type (wrong method? arithmetic slip? misread question?) determines what you need to drill next. This is where AI marking adds significant value: it gives you a question-by-question breakdown in under two minutes.

Get the 11 Plus Maths Fractions Worksheet

Our 11 Plus Maths Fractions worksheet was written to match the format and difficulty of real GL Assessment and CEM maths papers. It covers all eight fraction topic areas, includes a worked answer key, and is designed for children in Years 4–6 preparing for selective school entrance.

Once your child has completed the worksheet, upload a photo to our AI marking tool for instant question-by-question feedback. It identifies exactly which fraction topics need more work — so your next practice session targets the right things.

Quick Summary

• Fractions are one of the highest-weighted 11 Plus maths topics. Expect 8–12 direct questions per paper, plus fractions appearing inside percentages, ratio, and word problems.
• Eight topic areas to cover: simplifying, equivalent fractions, mixed numbers, fractions of amounts, adding and subtracting, multiplying, ordering, and converting between fractions, decimals and percentages.
• GL papers test fractions as standalone questions; CEM papers embed them in multi-step problems. Both require fully simplified answers.
• The #1 mistake is adding fractions by treating numerators and denominators separately (1/2 + 1/3 = 2/5). Drill common denominators until the process is automatic.
• Start in Year 4 with the basics. Build to full timed practice by Year 5. Use exam-standard worksheets — not textbooks — from Year 5 onwards.
• Review mistakes by type, not just score. Wrong method, arithmetic slip, and misread question all need different fixes.