How to Teach Fractions, Decimals and Percentages

By the Success Tutoring team · October 4, 2026

The key to teaching fractions, decimals and percentages is showing that they are three ways of writing the same thing. A half, 0.5 and 50% all describe the same amount. Start with pictures and real objects, learn a handful of common equivalents by heart, then practise converting between the three using money, measuring and shopping discounts.

Three names for the same amount

Children often learn fractions, decimals and percentages as separate topics, which makes them feel three times harder than they are. Draw a bar or a 10 × 10 grid and shade half of it. Then show that:

• As a fraction, it's 1/2 (one out of two equal parts).
• As a decimal, it's 0.5 (five tenths).
• As a percentage, it's 50% (50 out of 100).

The amount shaded never changes; only the way we write it does. Coming back to this picture again and again is the single most useful thing you can do.

Step 1: Make sure fractions are secure

Before converting, your child should understand that a fraction is a number of equal parts out of a whole, and that 2/4 is the same as 1/2. If this is still shaky, our guide on how to help a child with fractions and the Fraction Pizza game are good places to start.

Step 2: Connect decimals to place value

Decimals extend place value to the right of the decimal point. The first place is tenths, the second is hundredths. So 0.7 means 7 tenths (7/10) and 0.25 means 25 hundredths (25/100). Money is a perfect model: in many currencies, 0.50 of a dollar or pound is 50 cents or pence, which is half. The Place Value Quest and Money Match games build this understanding, and our guide on teaching place value explains the foundations.

Step 3: Percentages mean “out of 100”

“Per cent” literally means “per hundred”. A 10 × 10 grid makes this concrete: shade 30 squares and it's 30%, which is also 30/100, 3/10 and 0.3. Ask your child to shade different percentages and write each one in all three forms.

Step 4: Learn the key equivalents

A small set of facts covers most of what children meet in primary school. Knowing these by heart makes estimation and mental math much faster:

Step 5: Convert between them

• Fraction to percentage: make the bottom number 100. 3/5 = 60/100 = 60%.
• Percentage to decimal: divide by 100, so the digits move two places right of the point. 45% = 0.45.
• Decimal to fraction: read it aloud. 0.3 is “three tenths”, so 3/10.
• Tricky fractions: for fractions like 3/8, older children can divide the top by the bottom (3 ÷ 8 = 0.375).

Step 6: Find percentages of amounts

Start with 10%, which is the same as dividing by 10. From there, children can build almost any percentage:

• 50% is half.
• 25% is half of a half.
• 5% is half of 10%.
• 30% is 10% three times.
• 15% is 10% plus 5%.

So 15% of 80 is 8 + 4 = 12. This is a great mental math workout, and it's exactly how adults work out discounts and tips.

Everyday activities

• Shopping: “This is 25% off. How much will it cost?”
• Battery and progress bars: “The tablet is on 75%. What fraction is that?”
• Cooking: halving or quartering a recipe.
• Sport: “She scored 7 out of 10 shots. What percentage is that?”
• Measuring: 0.5 m is half a metre, 50 cm.

Common mistakes

• Thinking 0.25 is bigger than 0.5 because 25 is bigger than 5. Compare them as 25 hundredths and 50 hundredths. Rounding Rally also helps with decimal sense.
• Writing 1/4 as 0.4: go back to the grid to show a quarter is 25 squares.
• Thinking a percentage can't be over 100: 150% just means one and a half times the amount.

When do children learn this?

Children usually start simple fractions around ages 6 to 8, decimals around ages 8 to 10 and percentages around ages 9 to 11, with converting between all three becoming a focus in the last years of primary school.

Frequently asked questions