Definition
Measurement tool
A measurement tool is an instrument chosen to measure a particular attribute, such as length, time, temperature, capacity, or angle.
What it means
First decide what you need to measure, then choose the tool built for it. A ruler measures length, a clock measures time, a thermometer measures temperature, a balance measures mass, a measuring jug measures liquid capacity, and a protractor measures angle. A tool for the wrong attribute cannot give the measurement you need.
Remember it
Match the question to the tool: length → ruler, time → clock, angle → protractor.
Example
Mina wants the angle between two lines. She chooses a protractor, places its centre on the vertex, lines up the zero line, and reads 65°. A ruler would measure the line lengths, not the angle.
Watch for
A tool can read only within its scale and range; a 30 cm ruler cannot measure a 2 m table in one placement.
Common mix-up
A tool with more markings may allow a finer reading, but it still has to be used and aligned correctly.
Exact meaning
A measurement tool is an instrument used to compare an attribute with a scale or standard so the attribute can be reported with a number and unit. The tool must suit the attribute, range, and precision needed.