Page 105 - Viva ICSE Science 4 : E-book

ACTIVITY TIME
Let’s learn to measure length

Aim:

To measure the length of a pencil using a ruler
You Need:
A pencil, a ruler

What to Do:

• The pencil to be measured must be kept along the ruler to measure its length.
• Adjust one end of the pencil near the 0 cm mark of the ruler.
• Use your left hand to hold the ruler in its place.
• Now read the last number on the ruler till where the other end of your pencil reaches to see
how long it is.

• If it reaches the 8 cm mark, then the length of the pencil is 8 cm. But if the last number
on the ruler reaches 8 cm and beyond, like 5 smaller divisions more on the ruler, then the
length of the pencil is 8.5 cm.

In daily life, we measure length of rope, table, bed, curtains and many other things.

Measurement of Mass

Mass of an object is the amount of matter in it. It tells us how light or heavy a particular
object is. Kilogram (kg) is the standard unit of mass. The other commonly used unit of

mass is gram (g). Heavy objects are measured in terms of kilograms while light objects
are measured in terms of grams.

In earlier days, people used to measure mass of a substance using seeds, grains and

stones, but these were non-standard units and were not accurate. However, these days,
we measure the mass of an object using a beam balance or a weighing machine.

Weighing machine Electronic weighing machine Beam balance

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