2nd Class Mathematics Measurement Length, Weight and Capacity Measurement (Length, Weight and Volume)

LEARNING OBJECTIVES

This lesson will help you to:—

• measure length using non-standard units
• learn about standard units
• make difference between shorter and longer lengths.
• compare objects by their weights
• learn about simple balance.
• compare containers by observing their capacity.
• order containers as per their capacity.

Amazing Facts

• A kilometers is less than a mile.
• A small car weights about 1 tonn as 1 tonn = 1000 kilograms

QUICK CONCEPT REVIEW

MESURENENT OF LENGTH

Have you ever thought, how we can compare lengths of the two things? We can compare the lengths of two things by looking at them.

Out of the two chocolates shown, which one is longer?

It is easy to compare the length by keeping them side by side.

How can we measure length?

Let us discuss some methods to measure lengths.

Real Life Examples

• Measurement helps in taking proper medicine if you are ill, you need to take your medicine in the proper amount and quantity.
• Cooking of all forms is based on proper measurements. All the ingredients should be added in appropriate quantity.
• You purchase new clothes according to your size and length.

1. Non-standard Units

We can use hands pans, foot spans, cubits and paces to measure different lengths.

For example, if you have to measure the length of your study table. How will you do it?            

 You can use your hands pan to measure the length of table.

Now measure the length of floor of your room using your pace.

How much is it?

2. Arbitrary Units

We can also use objects like match - sticks, pencils, nail-pins etc. to measure the lengths of big objects.

For example, if you are asked to measure the length of your bat using a pencil. How will you do it?

Here, the length of bat is equivalent to the length of 8 pencils.

3. Standard Units

When we use nonstandard units like hand spans foot spans the measurement are bound to be different. Because the lengths of different people are different. So we need to use standard units.

We use standard units such as metre (m) and centimeter (cm) for accurate measurements of lengths. We can measure length of short objects like pencil using centimeter (cm) and for large objects like length of your room's door using metres (m).

1 m =100 cm

We can also measure length of an object using metre rod, metre tape or ruler.

MEASUREMENT OF WEIGHT

The weight of a heavier object is greater.

Let us take an example.

Can you hold a stick for a longer time? Yes you can! But if you have to hold a brick for longer time. Can you hold? It is difficult. Because brick is heavier than stick. It means weight of a brick is more than a stick.

Let us take another example.

Suppose you have to compare weights of an orange and an apple. Can you do? No, you cannot. For that you need a balance.

Gram

To find how heavy an object is, we need a fixed standard unit that anyone can use.

For light objects such as pencil, an apple etc., we use a unit called gram. It is written as ‘g’. We use some standard weights to measure weight of an object.

Kilogram

Heavier objects like a sack of rice can be weighed in kilograms (kg.)

                1 kg = 1000 g

MEASUREMENT OF CAPACITYNOLUME

Which container will hold more water? A glass or a bucket?

A bucket can hold more water because it is bigger in size.

Capacity/volume is the quantity of liquid (such as tea, water) that a container can hold.

How many glasses of water this water bottle can hold?

Suppose it can hold 4 glasses of water. We can say that the capacity of water bottle is 4 times the capacity of a glass of water.

Standard Unit of Capacity

We need a standard unit to measure the capacity of a container.

To measure the capacity of small containers such as spoon, bottle , we use millilitre (ml) as standard unit.

Litre (I) is used to measure capacity of large containers such as bucket, drum etc.

                \[1\,l=1000\,ml\]

Historical Preview

• In ancient times, the body ruled when it came to measuring. The length of a foot, and the width of a finger were all accepted measurements.