Page 11 - Science Class 6 Times Publication
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Measurement of length
The shortest distance between any two points is called length. The
SI unit of length is metre (m). Different instruments can be used to
measure length. For example, a ruler or scale is used to measure a
short distance, a metre rod or a measuring tape is used to measure
the long distance, etc.
We use different units to measure different distances. Some of the
units such as millimetre (mm), centimetre (cm) and decimetre (dm) are
smaller than the unit metre (m). Such units are called sub-multiples
of metre (m). Similarly, the units decametre(dam), hectometre (hm)
and kilometre(km) are larger than metre (m). Such units are called
multiples of metre (m).
0 cm 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
1 2 3 4 5 6
Scale Measuring tape
Multiples and sub-multiples of metre
The relation of metre (m) with its sub-multiples and multiples is
shown in the following table:
10 millimetres (mm) = 1centimetre (cm)
10 centimetres (cm) = 1decimetre (dm)
10 decimetres (dm) = 1metre (m)
10 metres (m) = 1decametre (dam)
10 decametres (dam) = 1hectometre (hm)
10 hectometres (hm) = 1kilometre (km)
Precautions while measuring the length
Small lengths can be measured by using standard scale. But there
may be some errors or mistakes during measurements due to the
following reasons :
1. Due to the wrong position of the scale: If the scale is not placed
over the measuring side properly, it gives wrong reading. So, the
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