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Improve Tuition · Foundation Maths · Year 5–9
Number · Fractions, Decimals & Percentages

Fractions, Decimals & Percentages

Three ways of saying “a bit of” something — converting, comparing and using them.

6 lessons · 35 questions (A–G) · 20 calculation + 15 word problems · no time pressure

Fractions, decimals and percentages are three ways of describing part of a whole, and each can be rewritten as the others — ½, 0.5 and 50% are the same value. Pupils most often slip on the conversions (lining up the decimal place, or turning a percentage into the wrong fraction) and on comparing values written in different forms.

At Improve Tuition, a qualified teacher shows how the three forms connect and a dependable way to convert between them, in small worked steps — with read-aloud, comfort spacing and a reading tint for pupils who take in maths more easily that way.

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Lesson 1

The big picture

Aim: See that a fraction, a decimal and a percentage can all describe the same amount, and know which move takes you between them.

A half can be written 1/2, 0.5 or 50% — the same amount in three different outfits. The skill is switching between them quickly.

Fraction → Decimaldivide top by bottom
Decimal → Percentage× 100
Percentage → Decimal÷ 100
Decimal → Fractionplace value, then reduce
Percentage → Fractionover 100, then reduce
Worked example
Show that 3/5, 0.6 and 60% are the same amount.
  1. 3/5 = 3 ÷ 5 = 0.6.
  2. 0.6 × 100 = 60%.
  3. All three describe the same amount.
Watch out
“× 100” is not “add two zeros.” 0.6 × 100 = 60, not 0.600. Move the decimal point two places.

Try one

Write 1/4 as a decimal and a percentage.

Show answer
A quarter means 1 ÷ 4.
1 ÷ 4 = 0.25.
Turn the decimal into a percentage: × 100.
0.25 × 100 = 25%.
Check: 25/100 = 1/4. ✓
Practise this now — Section A →
Lesson 2

Fraction → decimal

Aim: Turn any fraction into a decimal by dividing.

A fraction is a division waiting to happen: 7/8 means 7 ÷ 8. If the bottom is 10, 100 or 1000 you can read it off; otherwise, divide.

Worked example
Change 7/8 to a decimal.
  1. 7/8 means 7 ÷ 8.
  2. 7 ÷ 8 = 0.875.
  3. So 7/8 = 0.875.
  4. Check: 0.875 × 8 = 7, back to the top number. ✓
Watch out
Divide in the right order — the bottom is what you divide by. It is 7 ÷ 8, never 8 ÷ 7.

Try one

Write 1/5 as a decimal.

Show answer
A fraction means “top ÷ bottom”.
1 ÷ 5 = 0.2.
Check: 0.2 = 2/10 = 1/5. ✓
Practise this now — Section A →
Lesson 3

To and from percentages

Aim: Move between percentages and the other forms with × 100 and ÷ 100.

“Per cent” means “out of 100.” To turn something into a percentage, × 100; to turn one back, ÷ 100.

Decimal → %: 0.3 × 100 = 30%.
Fraction → %: 2/5 = 0.4, then × 100 = 40%.
% → decimal: 65% ÷ 100 = 0.65.
Worked example
Change 5/8 to a percentage.
  1. Make a decimal: 5 ÷ 8 = 0.625.
  2. × 100: 0.625 × 100 = 62.5.
  3. So 5/8 = 62.5%.
  4. Check: 5/8 is a bit more than a half, and 62.5% is a bit more than 50%. ✓
Watch out
Percentages can be over 100%. 13/10 = 1.3 = 130% — that just means more than one whole.

Try one

Write 0.08 as a percentage.

Show answer
To turn a decimal into a percentage, multiply by 100.
0.08 × 100 = 8%.
Check: 8% = 8/100 = 0.08. ✓
Practise this now — Section B →
Lesson 4

Decimal or percentage → fraction

Aim: Turn a decimal or percentage into a fraction in its lowest terms.

For a decimal, use place value for the bottom number (tenths → /10, hundredths → /100), then reduce. For a percentage, write it over 100 first.

Worked example
Change 35% to a fraction in its lowest terms.
  1. Over 100: 35% = 35/100.
  2. Divide top and bottom by 5: 35 ÷ 5 = 7, 100 ÷ 5 = 20.
  3. So 35% = 7/20.
  4. Check: 7 ÷ 20 = 0.35 = 35%, back where we started. ✓
Watch out
“Lowest terms” means keep cancelling until nothing divides both. 35/100 is not finished; 7/20 is.

Try one

Write 40% as a fraction in its lowest terms.

Show answer
Per cent means “out of 100”, so 40% = 40/100.
Divide top and bottom by 20.
40 ÷ 20 = 2 and 100 ÷ 20 = 5.
40/100 = 2/5.
Check: 2/5 = 0.4 = 40%. ✓
Practise this now — Section D →
Lesson 5

Percentage of an amount

Aim: Find a percentage of an amount.

Build the percentage you need from easy pieces: 10% is ÷ 10, and 1% is ÷ 100. Or turn the percentage into a decimal and multiply.

10% of £80 = £80 ÷ 10 = £8.
5% is half of 10% = £4.
So 15% of £80 = £8 + £4 = £12.
A percentage is just “out of 100” — here 25 of the 100 squares are shaded, so that is 25%.
Worked example
Find 15% of £200.
  1. 10% of £200 = £20.
  2. 5% is half of that = £10.
  3. 15% = £20 + £10 = £30.
Watch out
“% of” means multiply. 20% of 40 = 0.2 × 40 = 8 — not 40 ÷ 20 and not 40 − 20.

Try one

Find 25% of 60.

Show answer
25% is the same as a quarter.
A quarter of 60 is 60 ÷ 4.
60 ÷ 4 = 15.
Check: 15 is a quarter of 60. ✓
Practise this now — Section E →
Lesson 6

Ordering and comparing

Aim: Compare and order a mix of fractions, decimals and percentages.

You cannot compare different outfits directly. Change them all into one form — decimals are easiest — then they line up.

0½13/855%0.61
Turn them all into decimals and they line up: 3/8 = 0.375, 55% = 0.55, 0.61.
Worked example
Order 3/8, 55% and 0.61, smallest first.
  1. As decimals: 3/8 = 0.375, 55% = 0.55, 0.61 stays.
  2. 0.375 < 0.55 < 0.61.
  3. Order: 3/8, 55%, 0.61.
Watch out
Convert to compare, but give your final answer in the question’s original forms unless told otherwise.

Try one

Which is bigger, 0.7 or 72%?

Show answer
Put both in the same form — turn 0.7 into a percentage.
0.7 × 100 = 70%.
Compare 72% with 70%.
72% > 70%, so 72% is bigger.
Check: 0.72 > 0.70. ✓
Practise this now — Section G →
↑ Back to the lessons
Section A · Fractions to decimals
LEARNING OBJECTIVE · GRADE 2 · CALCULATION

Convert a fraction to a decimal.

Success criteria — I can:
  • read off tenths and hundredths
  • divide the top by the bottom for any fraction
1.Write 1/5 as a decimal.
Answer:
2.Write 9/20 as a decimal.
Answer:
3.Write 7/8 as a decimal.
Answer:
4.Write 13/25 as a decimal.
Answer:
5.Write 3/200 as a decimal.
Answer:
↑ Back to the lessons
Section B · Fractions to percentages
LEARNING OBJECTIVE · GRADE 3 · CALCULATION

Convert a fraction to a percentage.

Success criteria — I can:
  • make the fraction a decimal
  • multiply by 100
  • handle answers over 100%
6.Write 2/5 as a percentage.
Answer:
7.Write 7/20 as a percentage.
Answer:
8.Write 9/25 as a percentage.
Answer:
9.Write 5/8 as a percentage.
Answer:
10.Write 13/10 as a percentage.
Answer:
↑ Back to the lessons
Section C · Decimals to percentages
LEARNING OBJECTIVE · GRADE 2 · CALCULATION

Convert a decimal to a percentage.

Success criteria — I can:
  • multiply the decimal by 100
  • move the point two places right
11.Write 0.3 as a percentage.
Answer:
12.Write 0.08 as a percentage.
Answer:
13.Write 0.225 as a percentage.
Answer:
14.Write 1.6 as a percentage.
Answer:
15.Write 0.045 as a percentage.
Answer:
↑ Back to the lessons
Section D · Percentages to decimals & fractions
LEARNING OBJECTIVE · GRADE 3 · CALCULATION

Convert a percentage to a decimal or a fraction in lowest terms.

Success criteria — I can:
  • divide by 100 for a decimal
  • write over 100 then reduce for a fraction
16.Write 65% as a decimal.
Answer:
17.Write 4% as a decimal.
Answer:
18.Write 120% as a decimal.
Answer:
19.Write 40% as a fraction in its lowest terms.
Answer:
20.Write 35% as a fraction in its lowest terms.
Answer:
↑ Back to the lessons
Section E · Percentage of an amount
LEARNING OBJECTIVE · GRADE 3 · WORD PROBLEM

Find a percentage of an amount in context.

Success criteria — I can:
  • find 10% or 1% first
  • build the percentage you need
  • keep the right units
21.A coat costs £80. In a sale it is reduced by 10%. How much money is taken off, in pounds?
Answer:
22.A test has 60 questions. Sam answers 25% of them in the first hour. How many questions is that?
Answer:
23.A bill is £40. VAT of 20% is added. How much is the VAT, in pounds?
Answer:
24.A class of 30 pupils has 70% present one day. How many pupils are present?
Answer:
25.A jacket costs £200. A 15% deposit is paid. How much is the deposit, in pounds?
Answer:
↑ Back to the lessons
Section F · Real-life conversions
LEARNING OBJECTIVE · GRADE 4 · WORD PROBLEM

Convert between forms to solve real-life problems.

Success criteria — I can:
  • decide which form the question wants
  • convert accurately
  • give the answer in that form
26.In a test Mia scores 18 out of 25. Write her score as a percentage.
Answer:
27.A recipe says 0.75 of the flour should be wholemeal. Write 0.75 as a fraction in its lowest terms.
Answer:
28.A shop sign says “1/5 off everything.” Write 1/5 as a percentage.
Answer:
29.A phone battery is 0.4 charged. Write this as a percentage.
Answer:
30.On a quiz Leo scores 31/50. Write his score as a percentage.
Answer:
↑ Back to the lessons
Section G · Ordering & comparing
LEARNING OBJECTIVE · GRADE 5 · WORD PROBLEM

Compare and order a mix of fractions, decimals and percentages.

Success criteria — I can:
  • change everything into one form
  • compare the values
  • answer the exact question asked
31.Which is smallest: 0.7, 3/4 or 72%? Write it as it appears in the list.
Answer:
32.Which is largest: 2/5, 0.45 or 38%? Write it as it appears in the list.
Answer:
33.Order 0.3, 1/4 and 28% from smallest to largest. What is the middle value?
Answer:
34.Shop A offers “1/4 off,” Shop B offers “20% off.” Which is the bigger discount, as a percentage?
Answer:
35.Which is bigger, 5/8 or 60%? Give the bigger value as a percentage.
Answer:
0 of 35 answered
Guide

What is the link between fractions, decimals and percentages?

A fraction, a decimal and a percentage can all describe the same part of a whole. Three quarters can be written as ¾, as 0.75, or as 75% — same value, three notations.

To convert: a fraction becomes a decimal by dividing the top by the bottom; a decimal becomes a percentage by multiplying by 100; and a percentage becomes a fraction by writing it over 100 and simplifying. To compare values in different forms, turn them all into the same form first.

Common mistakes. Misplacing the decimal point when multiplying or dividing by 100, forgetting to simplify a fraction, or comparing a fraction and a percentage without converting them first.

Common questions
How do you turn a fraction into a percentage?
Divide the top number by the bottom to get a decimal, then multiply by 100. For example, 3 ÷ 4 = 0.75, and 0.75 × 100 = 75%.
How do you turn a percentage into a fraction?
Write the percentage over 100 and simplify. For example, 40% = 40/100 = 2/5.
How do you turn a decimal into a percentage?
Multiply by 100, which moves the decimal point two places to the right. So 0.6 becomes 60%.
How do you compare a fraction with a percentage?
Convert both to the same form, usually percentages, then compare. For example, 3/5 = 60%, which is more than 55%.
How do you find a percentage of an amount?
Turn the percentage into a decimal and multiply. For example, 20% of £30 is 0.2 × 30 = £6.
Stuck on this topic?

A teacher can find the exact gap

Practising fractions, decimals and percentages on your own is a strong start. If the same marks keep slipping, a qualified teacher can pinpoint the precise gap and fix it. Improve Tuition offers one-to-one maths tuition with our maths tutors in Batley and online — the first assessment is free.

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