___________
Maths
Estimation and rounding

Starter quiz

  • __________ shows how precise a number or measurement is.
    • An approximation  ✓
    • A degree of accuracy
    • A guess
    • A guess-stimate
    • Rounding
  • Match each number to its rounded value.
    • 323
      ⇔
      320 (2 s.f.) ✓
    • 294.82
      ⇔
      294.8 (1 d.p.) ✓
    • 291
      ⇔
      290 (2 s.f.) ✓
    • 294.829
      ⇔
      294.83 (2 d.p.) ✓
  • A square plot of grass has a length of 2.89 m to 2 decimal places. Select the correct estimate for the area of the square grass plot.
    • 3 × 3 = 9 m²  ✓
    • 3 × 3 = 6 m²
    • 3 + 3 + 3 + 3 = 12 m²
    • 3 + 3 + 3 + 3 = 12 m
  • Match each number to its rounded value.
    • 0.0038903
      ⇔
      0.0039 (2 s.f.) ✓
    • 0.038903
      ⇔
      0.04 (2 d.p.) ✓
    • 0.00038903
      ⇔
      0.0004 (1 s.f.) ✓
    • 0.000038903
      ⇔
      0.000039 (2 s.f.) ✓
  • Which of the following are correct, quick estimate calculations for {4.56\times8.95} \over {0.498}?
    • {5\times9} \over {0.5} = 90  ✓
    • {5\times10} \over {0.5} = 25
    • {5\times9} \over {0.5} = 22.5
    • {5\times10} \over {0.5} = 100  ✓
  • Match each calculation to its correct approximate answer.
    • {19.89} \over {0.498}
      ⇔
      \approx 40 ✓
    • {19.89} \over {0.2134}
      ⇔
      \approx 100 ✓
    • {19.89} \over {0.1111}
      ⇔
      \approx 200 ✓
    • {19.89} \over {2.073}
      ⇔
      \approx 10 ✓
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