Adding and subtracting fractions with the same bottom number within one whole · seed 1 · A4, ink-friendly. The answer key prints on its own page for grown-ups.

When the bottom numbers match

Mathematics · Fractions · ages 7-8
Name ______________________   Date ____________

  1. 6/8 − 3/8 = ?

    • 9/8
    • 3/8
    • 3/4

  2. Join two ninth-pieces and one more ninth-piece of the same whole. Which equation matches?

    • 2/9 + 1/9 = 3/9
    • 2/9 - 1/9 = 1/9
    • 2/9 + 1/9 = 3/18
    • 2/9 + 1/9 = 2/9

  3. Which subtraction leaves 2/7?

    • 5/7 - 1/7
    • 6/7 - 3/7
    • 6/7 - 4/7
    • 4/7 - 3/7

  4. 2/5 + 2/5 = ?

    • 4/5
    • 4/10
    • 2/5

  5. What is 8/9 - 3/9?

    • 5/18
    • 5/9
    • 6/9
    • 3/9

  6. Which pair of fractions can you add just by adding the top numbers?

    • 3/5 and 1/5
    • 3/5 and 1/4
    • 3/5 and 1/6

  7. Mia eats 3/8 of a pizza. Her brother eats a different 1/8 of the same pizza. How much do they eat together?

    • 2/8
    • 3/8
    • 4/16
    • 4/8

  8. A pizza was cut into 10 equal slices. Seven slices remain. People eat two more slices. What fraction of the original pizza remains?

    • 9/10
    • 5/20
    • 5/10

  9. Diego calculated 2/5 + 2/5 and got 4/10. What mistake did he make?

    • He forgot to add the top numbers
    • He added the bottom numbers too
    • He used the wrong fraction

  10. Which pair adds up to exactly one whole?

    • 4/9 + 5/9
    • 4/9 + 4/9
    • 3/9 + 4/9
    • 2/9 + 4/9
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Answer key

For grown-ups. Fold this page away before handing over the rest.

When the bottom numbers match W1-mt_a1FdAsRKOF-s1

  1. 3/8 · Subtract the top numbers: 6 − 3 = 3. The bottom number stays 8, so the answer is 3/8.
  2. 2/9 + 1/9 = 3/9 · Joining means adding these amounts. Two pieces and one piece make three ninth-pieces.
  3. 6/7 - 4/7 · 6 - 4 = 2, so 6/7 - 4/7 leaves 2/7.
  4. 4/5 · Add the top numbers: 2 + 2 = 4. The bottom number stays 5.
  5. 5/9 · 8 - 3 = 5. The pieces remain ninths, so the answer is 5/9.
  6. 3/5 and 1/5 · You can only add top numbers directly when the bottom numbers match. Only 3/5 and 1/5 share a bottom number of 5.
  7. 4/8 · The separate amounts are eighths of the same pizza. 3 + 1 = 4, so they eat 4/8.
  8. 5/10 · Seven slices minus two leaves five. Each slice is one tenth of the original pizza, so 5/10 remains.
  9. He added the bottom numbers too · Diego added both the top and bottom numbers. The bottom number should stay 5, so the correct answer is 4/5.
  10. 4/9 + 5/9 · 4/9 + 5/9 = 9/9 = 1. The other pairs fill eight, seven or six ninths.
Worksheet · LightMySky