Class 3 fractions: what part is left?

By AI Study Guru · Published 2 October 2026

What do the top and bottom numbers mean?

In the fraction 4/6, the top number, 4, is the numerator. It counts the slices we are talking about. The bottom number, 6, is the denominator. It tells us how many equal slices made the whole pizza.

The parts must be equal. Four large slices and two tiny slices do not make six equal parts, so counting slices alone would not tell us the fraction of that pizza.

Worked example: 6 slices, 2 eaten

Question: A pizza has 6 equal slices. You eat 2 slices. What fraction of the whole pizza is left?

1. Start with 6 slices.
2. Take away the 2 eaten slices: 6 − 2 = 4.
3. Put the 4 remaining slices over the original total of 6: 4/6.

So 4/6 of the pizza is left. The numerator is 4 and the denominator is 6. We keep 6 on the bottom because we are still comparing with the original whole pizza.

Why isn't the answer 3/6?

If you wrote 3/6, check the subtraction first. Count back two steps from 6: 5, then 4. That means 4 slices are left. Your denominator of 6 was right; the number of slices left needed correcting.

If you wrote 4/4, you counted the remaining slices correctly. But the question asks about the original whole pizza, which had 6 slices. Use 6 as the denominator.

Your turn: try one question at a time

Question 1: pizza slices

A pizza has 8 equal slices. You eat 3. What fraction of the whole pizza is left?

Check question 1

8 − 3 = 5 slices remain, so the fraction left is 5/8. The numerator is 5 and the denominator is 8.

Question 2: a group of mangoes

Riya has 8 mangoes and gives 3 to a friend. What fraction of the mangoes did she give away?

Check question 2

She gave away 3/8 of the mangoes. This question asks for the number given away, so 3 goes on top. We are counting mangoes, not comparing their weights.

Question 3: a little more challenging

A box has 12 chocolates. Aarav eats 5 and his sister eats 2. What fraction of the chocolates is left?

Check question 3

They eat 5 + 2 = 7 chocolates altogether. Then 12 − 7 = 5 remain. The fraction left is 5/12.

A quick checking habit

Underline what the question asks: eaten, given away, or left. Count that amount for the numerator. Use the original number of equal parts or counted objects for the denominator. In the pizza example, the eaten and remaining slices should add back to the original total: 2 + 4 = 6.

You may later learn that 4/6 can also be written as 2/3. Both describe the same amount. For this exercise, 4/6 shows the four remaining slices out of the original six directly.

Practise with your study helper

Send this request to AI Study Guru on Telegram: “Give me one Class 3 fraction question. Wait for my answer, check my subtraction and fraction separately, and explain any mistake simply.” If the question feels easy, ask for one with two subtraction steps.

Parents can use paper circles cut into equal pieces to make the same examples hands-on. See primary-school study help or explore more study guides.