Page 132 - Revised Maths Wisdom Class - 3

10 Length

Warm Up

● Length of an object denotes “how long an object is".
● Standard unit of length is metre and it is denoted as 'm'.
● Other units of length are centimetre and kilometre
which are denoted as 'cm' and 'km'.
© G. Ram Books (P.) Ltd.©
● In earlier days, non-standard units like handspan,
cubit, pace, etc. were used to measure length of
various objects. Handspan Cubit Pace

When we measure the length using handspan, cubit, pace or other non-standard units,
we fi nd that measurements diff er from person to person. Therefore, standard units of
length have been defi ned to avoid confusion and to ensure that a certain length remains
same all over the world.

Units of Length

Metre

The standard unit of length is metre. It is denoted as ‘m’. Height of a wall, pole, fabric,
etc. are measured in metres.

Centimetre

The next unit which is commonly used is centimetre. It is the smaller unit of length and
is denoted as ‘cm’. Length of pencil, pen, ruler, paper, etc. can easily be measured in ‘cm’.

Kilometre
Kilometre is the bigger unit of length and is denoted as ‘km’. Distance between two

villages, towns or cities are measured in kilometre.

Tools for Measuring Length

Smaller lengths are measured by ruler.

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
cm
inch
5(zero) mark and fi nd
To measure the length of an object we keep the tip of the object at 0 6
2
3
4
0
1
the mark on ruler that matches with the end point of the object. This gives the length of
the object.