of Mass (Weight)
everyday life we usually compare the mass of different objects. We can compare
the mass of two things by lifting or holding the objects with our hands and
find out which object is heavier or lighter. But everything we can lift or hold
and this type of measurement are not accurate, they are just rough estimates.
Example: If we hold pencil on one hand and book on
other hand, we can easily say that book is heavier than the pencil.
the mass of an object is also known as weighing the object. We use
different weighing scales or weighing machines to weigh objects.
In case of balance scale, when two objects weigh
the equal, the two pans of the weighing scales are said to be balanced and stay
at the equal level and when one object heavy and other is lighter, the pan with
the heavier object goes down and the pan with the lighter object goes up.
need to use suitable units to measure the masses of objects. The standard unit of
mass is the gram. We write gram as ‘g’.
grams put together make a bigger unit called kilogram. Kilogram is
written as ‘kg’ in short.
measure lighter objects in grams whereas heavier objects in kilograms.
Example 1: Three friends weigh 28 kg, 30 kg and
32 kg. Find their total weight.
Example 2: Ria’s mom bought 3 kg grapes, 2 kg oranges,
2 kg apples and put them in her bag. Find the total weight of the fruits in her