Measurement of Length

Length means how long something is. We see many things around us. Some are short in length such as paper clip, pencil, pen, notebook etc., some are long in length such as tree, electric pole, cloth, room, train track and some are very long such as distance between two places. We need to select suitable unit to measure these lengths.

Non Standard Units of Measurement

In early days body parts were used to measure length. But measurements taken by these means are not accurate and consistent. If we use our hand span to measure length, the measurement taken by different person will vary as our hand spans are not equal.

Example: a child hand span is smaller than the adult. So, hand span, hand, foot and cubit are not standard units of measurement.

Standard Units of Measurement

We observed that nonstandard unit of measurement does not give same results. So, we need to use some standard units for measuring lengths. Otherwise the measurements of an object will be different when measured in different ways. We use different units of length to measure different lengths.

Example:

To measure small Lengths such as lengths of a pen,pencil,paint brush and book .We use centimetre . Short form of centimetres is cm.

To measure the length of a building length of a saree lengths of a room and so on we use metre .of a room and so on .We use metre . short form of metre is m

To measure long distance such as the distance between your House and school,we use kilometre.short form of kilometre