Coaching Centre
Units and accuracy of measurement
Converting units of length, area and volume, limits of accuracy, absolute error and choosing sensible precision.
Converting area and volume units
Convert $2.5$ m² to cm².
Limits of accuracy
A measurement is only as accurate as the instrument. The absolute error is half the smallest unit on the scale. A length of $12.4$ cm measured to the nearest mm lies between $12.35$ cm and $12.45$ cm.
A rope is $8$ m to the nearest metre. Give its limits of accuracy.
Convert $2.5$ m² to cm².
$\times 10\,000$.
$8$ m to the nearest metre. Lower and upper limits?
$\pm 0.5$ m.
Convert $3$ m³ to cm³.
$\times 100^3$.
Convert $450$ mm to m.
$\div 1000$.
Absolute error when measuring to the nearest $0.1$ cm?
Half of $0.1$.
$12.4$ cm to the nearest mm. Lower and upper limits?
$\pm 0.05$ cm.
Convert $5$ cm² to mm².
$\times 100$.
Convert $2400$ cm³ to litres.
$1000$ cm³ $= 1$ L.
New numbers every time. Keep going until you get five in a row.