Definition
Measurement
Measurement compares an attribute with a chosen unit and reports the result as a number together with that unit.
What it means
Decide what attribute you are measuring, choose a suitable unit and tool, compare the attribute with equal units, then report both the number and the unit. The unit matters because the same object can have different measurement numbers when different-sized units are used.
Remember it
A complete measurement names the attribute and gives a number with its unit.
Example
A pencil begins at the 2 cm mark and ends at the 11 cm mark on a ruler. Its length is 11 − 2 = 9 cm. Subtracting the starting reading works even though the pencil did not begin at zero.
Watch for
The number 8 by itself is not a complete measurement; it could mean 8 cm, 8 seconds, 8 litres, or something else.
Common mix-up
Starting away from zero is allowed only when you subtract the starting reading from the ending reading.
Exact meaning
Measurement is the process of comparing a specified attribute of an object, event, or quantity with a chosen unit or scale to assign a numerical value and unit to that attribute.