Learn · Mathematics · Class 4

Fractions

Equal parts of a whole, and why a bigger bottom number means smaller pieces.

8 parts
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Turn this on and each part is read out as you reach it.
📘 DefinitionWhat the two numbers meanPart 1 of 8
The same whole, cut differently1 wholehalvesquarterseighthsMore pieces means each piece is SMALLER
The same whole cut into halves, quarters and eighths.
🔍 In detailEquivalent fractionsPart 3 of 8
✏️ Worked exampleAdding fractions with the same bottomPart 4 of 8
🌍 In the real worldFractions every dayPart 5 of 8
⚠️ Common mistakesWhere it usually goes wrongPart 6 of 8
✅ SummaryWhat to rememberPart 7 of 8
A round flatbread cut into equal slices, which is what the bottom number of a fraction counts. Photo: Crisco 1492, CC BY-SA 4.0, via Wikimedia Commons.
A round flatbread cut into equal slices, which is what the bottom number of a fraction counts. Photo: Crisco 1492, CC BY-SA 4.0, via Wikimedia Commons.
1📘 DefinitionPart 1 / 8

What the two numbers mean

A fraction shows equal parts of a whole.

3/4 → the 4 says how many equal parts
the 3 says how many you have

The bottom number is the denominator, the top is the numerator.

The word equal matters. Four pieces of very different sizes are not quarters.

2🧩 The partsPart 2 / 8

Bigger bottom, smaller pieces

This is the idea that trips most people up.

Cut a roti into 8 pieces and each is smaller than if you cut it into 4. So 1/8 is less than 1/4, even though 8 is bigger than 4.

The more you cut something, the smaller each piece becomes.

3🔍 In detailPart 3 / 8

Equivalent fractions

Different fractions can name the same amount.

1/2 = 2/4 = 4/8

Look at the bars: half the strip is covered every time.

You make an equivalent fraction by multiplying top and bottom by the same number. Multiply only one and you change the amount.

1/2 × 3/3 = 3/6
4✏️ Worked examplePart 4 / 8

Adding fractions with the same bottom

Question. 2/5 + 1/5

Step 1: check the bottoms match. Both are fifths, so the pieces are the same size and can simply be counted.

Step 2: add the tops only.

2/5 + 1/5 = 3/5

Why the bottom stays the same: you are counting pieces, and the pieces have not changed size. Two fifths plus one fifth is three fifths, exactly like 2 apples plus 1 apple is 3 apples.

If the bottoms are different, the pieces are different sizes and you cannot count them together yet. That comes in Class 5.

5🌍 In the real worldPart 5 / 8

Fractions every day

Food. Half a roti, a quarter of a cake, three-quarters of a glass.

Time. Quarter past, half past, quarter to. An hour cut into four.

Sharing. One pizza between three friends is 1/3 each, and this is where children first meet fractions naturally.

Shopping. "Half price" is a fraction doing real work on your money.

6⚠️ Common mistakesPart 6 / 8

Where it usually goes wrong

  • "1/8 is bigger than 1/4 because 8 > 4." Backwards. More pieces, smaller pieces.
  • Adding tops and bottoms. 1/4 + 1/4 is 2/4, not 2/8.
  • Forgetting the parts must be equal.
  • Changing only the top or only the bottom when making an equivalent fraction.
7✅ SummaryPart 7 / 8

What to remember

  • Bottom = how many equal parts · top = how many you have.
  • Bigger bottom = smaller pieces.
  • 1/2 = 2/4 = 4/8, same amount, different names.
  • Same bottom → add the tops only.
8✏️ Worked examplePart 8 / 8

Watch one worked through

Here is one done slowly, with the reason for every move. Then one for you.

Let me show you

Which is bigger, 1/4 or 1/6? Then work out 2/7 + 3/7.

  1. 1/4 vs 1/6
    For the comparison, picture one roti cut into 4, and another cut into 6.
    A fraction with 1 on top is one piece out of that many. Picturing the cut stops you reading the bottom number as a size.
  2. more pieces = smaller pieces 1/4 > 1/6
    Cutting into 6 makes smaller pieces than cutting into 4, so 1/4 is bigger.
    A bigger bottom number means more pieces, so each piece is smaller. This is backwards from whole numbers, which is exactly why it is the commonest mistake in the topic.
  3. 2/7 + 3/7 bottoms: 7 = 7 ✓
    For the addition, check the bottoms match. Both are sevenths.
    You can only add pieces that are the same size. If the bottoms differ you have to make them match first.
  4. 2/7 + 3/7 = 5/7
    Add the tops only: 2 + 3 = 5. The bottom stays 7.
    You are counting pieces, not changing their size. Adding the bottoms too would say the pieces got smaller while you were adding them, which cannot happen.

Answer: 1/4 is bigger, and 2/7 + 3/7 = 5/7

Now you try

Work out 4/9 + 2/9.

Show the answer

6/9

Practise Fractions

Everything on QuizByt for Class 4 Mathematics that goes with this lesson: read it first, then test yourself while it is fresh.

🧠 5 quizzes on Fractions (2 easy, 2 medium, 1 hard)

Work up from easy to hard: the hard quiz asks the Class 4 exam-style questions on Fractions.

🖨️ Printable worksheet

Fractions on paper for Class 4, with room to write the working out. Preview the first page free.

🎮 Games for Class 4 Mathematics

Number and logic games at the right level for Class 4. Passing a quiz on Fractions earns the credits that open them.

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