Length word problems within 100 · seed 1 · A4, ink-friendly. The answer key prints on its own page for grown-ups.
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Solving length word problems

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

  1. A green strip is 31 cm long. A yellow strip is 24 cm long. How many centimetres longer is the green strip?

    Answer: ______________

  2. Two strips, 22 cm and 13 cm long, are placed end to end without overlap. Let n be their total length in centimetres. Which equation matches?

    • 22 + 13 = n
    • 22 - 13 = n
    • n + 22 = 13
    • 13 - 22 = n

  3. A ribbon is 30 cm long. You cut off 10 cm. How long is it now?

    • 10 cm
    • 20 cm
    • 40 cm

  4. In a word problem, if a piece is cut off a rope, you should add the numbers to find what's left.

    Circle one:   True   False

  5. After 17 cm is cut off a string, 46 cm is left. How many centimetres long was the string before the cut?

    Answer: ______________

  6. A board is 68 cm long. After a piece is cut off, 41 cm is left. Let n be the cut piece's length in centimetres. Which equation matches?

    • n − 68 = 41
    • 68 + n = 41
    • 68 − n = 41

  7. A 36 cm strip gains a piece at its end without overlap. The total is 64 cm. How long is the added piece?

    • 18 cm
    • 36 cm
    • 28 cm
    • 100 cm

  8. A string starts at 86 cm and loses 29 cm. Ben uses n for the length left in centimetres and writes n = 86 - 29. Does his equation match?

    Circle one:   True   False

  9. Mia says: 'A ribbon is 24 cm long. I add a 16 cm piece, so the total is 24 − 16 = 8 cm.' What mistake did Mia make?

    • She subtracted instead of adding the piece.
    • She added instead of subtracting the piece.
    • She found the total by adding both lengths.

  10. A rope starts at 100 cm. First, 23 cm is cut off. After a second cut, 49 cm is left. How many centimetres were removed in the second cut?

    Answer: ______________

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Answer key

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

Solving length word problems W1-mt_DLcEzmmj2r-s1

  1. 7 · Find the length difference: 31 - 24 = 7. The green strip is 7 cm longer.
  2. 22 + 13 = n · The lengths join without overlap, so add: 22 + 13 = n. The total is 35 cm.
  3. 20 cm · Cutting off means subtract: 30 − 10 = 20 cm left.
  4. False · Cutting off makes the rope shorter, so you subtract, not add.
  5. 63 · Put the removed length back: 46 + 17 = 63. The string started at 63 cm.
  6. 68 − n = 41 · Start length minus the missing piece equals what's left: 68 − n = 41.
  7. 28 cm · Subtract the starting length from the total: 64 - 36 = 28 cm.
  8. True · Yes. The remaining length equals 86 - 29. The unknown can be written before the equals sign.
  9. She subtracted instead of adding the piece. · Adding a piece makes the ribbon longer, so Mia needed to add, not subtract.
  10. 28 · The first cut leaves 100 - 23 = 77 cm. The second cut removes 77 - 49 = 28 cm.
Worksheet · LightMySky