11+ Fractions, Decimals & Percentages: Full Guide

Fractions, decimals, and percentages (FDP) form a core component of all 11+ maths examinations, including those set by CEM and GL Assessment. A strong understanding of these interlinked concepts is crucial for success, as they appear in various question formats, from direct calculations to worded problems.

This guide will break down the essential knowledge required, offer practical advice for preparation, and provide example questions to help your child build confidence and proficiency in this vital area of the 11+ maths syllabus.

Maths: fractions 11+ at a glance

Core Concepts and Conversions

Understanding the relationship between fractions, decimals, and percentages is the foundation. Children need to be proficient in converting between these forms rapidly. For example, knowing that 1/2 is 0.5 and 50%, or that 0.25 is 1/4 and 25%, is fundamental.

Focus on common equivalences first, then move to more complex ones. Practice converting fractions to decimals through division, and decimals to percentages by multiplying by 100. Similarly, percentages can be converted to decimals by dividing by 100, and then to a fraction in its simplest form.

Calculations with FDP

The 11+ will test various operations involving fractions, decimals, and percentages. For fractions, this includes addition, subtraction, multiplication, and division, ensuring answers are in their simplest form. Remember that to add or subtract fractions, they must share a common denominator.

Decimal calculations will involve all four operations, often requiring careful alignment of decimal points. Percentage calculations frequently involve finding a percentage 'of' an amount, expressing one number as a percentage of another, and percentage increases/decreases.

Tips for 11+ Success

Consistent practice is key. Encourage your child to identify FDP within different types of maths problems to improve their application skills. Timed practice will help them manage exam pressure and improve their speed and accuracy. Reviewing incorrect answers to understand the mistake is as important as getting them right.

Encourage the use of estimation to check answers where appropriate, particularly for percentage calculations. For instance, if finding 48% of 200, estimating 50% of 200 (which is 100) will give a good approximation. Finally, ensure they are comfortable reading and interpreting worded problems that feature FDP concepts, as these are common in both CEM and GL exams.

Try Maths: fractions 11+ practice questions

Question 1
What is 3/5 as a percentage?
Answer: 60%. To convert a fraction to a percentage, divide the numerator by the denominator and multiply by 100. (3 ÷ 5) × 100 = 0.6 × 100 = 60%.
Question 2
Calculate 20% of £350.
Answer: £70. To find 20% of £350, you can calculate (20/100) * 350. (1/5) * 350 = £70. Alternatively, find 10% (£35) and double it.
Question 3
Convert 0.125 to a fraction in its simplest form.
Answer: 1/8. 0.125 can be written as 125/1000. To simplify, divide both numerator and denominator by their greatest common divisor, which is 125. 125 ÷ 125 = 1, and 1000 ÷ 125 = 8. So, 0.125 = 1/8.
Question 4
A shirt originally costs £40. It is reduced by 25% in a sale. What is the new price?
Answer: £30. First, calculate 25% of £40: (25/100) * 40 = (1/4) * 40 = £10. Then, subtract this reduction from the original price: £40 - £10 = £30.

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Frequently asked questions

Are calculators allowed in 11+ exams for FDP questions?

No, calculators are not permitted in any 11+ maths exam, including those sections focusing on fractions, decimals, and percentages. All calculations must be performed mentally or using written methods.

What is the difference in FDP questions between CEM and GL exams?

GL Assessment exams often feature dedicated sections for FDP, directly testing conversions and calculations. CEM exams tend to embed FDP within more complex, multi-step problem-solving questions, requiring a deeper application of the concepts rather than straightforward calculations.

How can my child improve their speed in FDP calculations?

Regular, timed practice is essential. Use online quizzes or workbooks with time limits. Encourage mental maths strategies, such as using known equivalences (e.g., for 25%, think 'divide by 4'). Consistent revision of core conversions will also build speed.

Should my child memorise common FDP equivalences?

Yes, absolutely. Memorising common equivalences like 1/2 = 0.5 = 50%, 1/4 = 0.25 = 25%, 3/4 = 0.75 = 75%, 1/5 = 0.2 = 20%, and 1/10 = 0.1 = 10% will significantly speed up their problem-solving and reduce errors under exam conditions.