Measuring with different units · seed 1 · A4, ink-friendly. The answer key prints on its own page for grown-ups.

Measuring with different units

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

  1. A shelf is 6 hand-spans long. Each hand-span is 10 cm. How long is the shelf in centimetres?

    Answer: ______________

  2. A desk is 120 cm long. About how many inches is that?

    • About 120 inches
    • About 12 inches
    • About 50 inches
    • About 300 inches

  3. You measure a table with a centimetre ruler and get 80. You measure it again with an inch ruler. Will the inch number be bigger or smaller than 80?

    • Bigger
    • Smaller
    • The same

  4. Which unit is smaller: a centimetre or an inch?

    • Centimetre
    • Inch
    • They are the same

  5. A desk is 100 cm long. A book is 25 cm long. How many book-lengths fit along the desk?

    Answer: ______________

  6. Which sentence is true when you measure the same object with two different units?

    • The object changes size each time
    • The bigger unit always gives a bigger number
    • The smaller unit always gives a bigger number

  7. An inch is longer than a centimetre. Will a length in centimetres be greater or less than in inches?

    • Greater
    • Less
    • Equal
    • Cannot tell

  8. A stick is 30 cm long. Sam predicts it is more than 30 inches long. Is Sam right?

    Circle one:   True   False

  9. Ravi says: 'My rope is 6 metres long, so it must also be 6 centimetres long.' What is wrong with what Ravi said?

    • Nothing is wrong
    • A metre and a centimetre are different sizes, so the numbers can't be the same
    • Ropes cannot be measured in metres

  10. A ribbon is 40 cubes long. Each cube is 2 cm. How long is the ribbon in centimetres?

    Answer: ______________

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Answer key

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

Measuring with different units W1-mt_jHv4BgRK8B-s1

  1. 60 · 6 lots of 10 cm make 60 cm.
  2. About 50 inches · An inch is about two and a half centimetres, so 120 cm is about 50 inches.
  3. Smaller · Inches are a bigger unit than centimetres, so you need fewer of them. The number gets smaller.
  4. Centimetre · A centimetre is smaller than an inch, so it takes more centimetres to cover the same length.
  5. 4 · 100 / 25 = 4 book-lengths.
  6. The smaller unit always gives a bigger number · Smaller units need more copies to cover the same length, so their count comes out bigger.
  7. Greater · Centimetres are smaller, so more of them fit and the number is greater.
  8. False · Sam is wrong. Inches are longer than centimetres, so the inch count must be less than 30, about 12.
  9. A metre and a centimetre are different sizes, so the numbers can't be the same · A metre is much bigger than a centimetre, so measuring the rope in centimetres would give a much larger number, not the same one.
  10. 80 · 40 lots of 2 cm make 80 cm.
Worksheet · LightMySky