Accurate Measurement · seed 1 · A4, ink-friendly. The answer key prints on its own page for grown-ups.

Taking and checking measurements

Science · Scientific Inquiry · ages 9-11
Name ______________________   Date ____________

  1. Keeping the release point and finish line the same helps make ramp timings comparable repeats.

    Circle one:   True   False

  2. Which ruler can show smaller length differences when measuring a leaf?

    • A ruler marked every centimetre
    • A ruler marked every millimetre
    • A ruler with no readable markings
    • A ruler showing only its total length

  3. Which tool measures how hot a cup of tea is?

    • Thermometer
    • Digital stopwatch
    • Centimetre ruler

  4. A reading that is very different from the others might come from a measurement mistake.

    Circle one:   True   False

  5. Length readings are 17 cm, 19 cm, 18 cm and 17 cm. What is their range in centimetres?

    Answer: ______________

  6. Three stopwatches time the same race and show 12.1 s, 12.3 s and 18.9 s. Which reading is anomalous?

    • 12.1 s
    • 12.3 s
    • 18.9 s

  7. A note says the stopwatch kept running after a marble reached the finish. How should this recorded time be handled?

    • Keep the value in the mean and remove the timing note
    • Replace the recorded value with a guess near the other times
    • Keep the value and note; omit it from the mean; repeat
    • Delete the recorded value and its timing note, then guess

  8. Three repeat times are 11 s, 13 s and 12 s. What is their mean in seconds?

    Answer: ______________

  9. A strip has a checked reference length of 10 cm. Tom repeatedly reads 11 cm. What should he check next?

    • Repeat without checking the setup
    • Check zero and endpoint alignment
    • Report 11 cm because repeats agree

  10. Mass readings are 34 g, 35 g, 34 g and 50 g. A note confirms that 50 g came from a different object by mistake. Keep that record but exclude it from this total. Add the other readings in grams.

    Answer: ______________

LightMySky · lightmysky.comW1-mt_Psun-u_lPf-s1

Answer key

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

Taking and checking measurements W1-mt_Psun-u_lPf-s1

  1. True · These conditions define the journey being timed. Keeping them the same helps you compare repeat timings.
  2. A ruler marked every millimetre · Millimetre divisions are smaller than centimetre divisions. Ten millimetres make one centimetre.
  3. Thermometer · A thermometer measures temperature. A stopwatch measures time and a ruler measures length.
  4. True · A mistake is one possible cause of an anomalous reading. A change in conditions or real variation is also possible.
  5. 2 · The range is the largest reading minus the smallest: 19 − 17 = 2 cm.
  6. 18.9 s · 18.9 s is far from the closely grouped 12.1 s and 12.3 s readings. Its cause needs investigation.
  7. Keep the value and note; omit it from the mean; repeat · The documented timing slip means this value did not measure the planned journey. Keep its record, explain the exclusion and repeat.
  8. 12 · The total is 36 s. Divide by the three readings to get a mean of 12 s.
  9. Check zero and endpoint alignment · Agreement shows repeatability, but the readings differ from the reference. A shared alignment problem could affect every reading.
  10. 103 · The documented object mix-up justifies excluding 50 g from this total. The accepted values total 34 + 35 + 34 = 103 g.
Worksheet · LightMySky