Numbers with Units

You must have seen fish in the sea, and in aquariums.

Observe the images of fish shown here.

The fishes are drawn using rectangles, triangles and pentagons.

Observe that all the fishes in the images look almost same in size.

Fish in reality are of different sizes.

Some fish might be heavier, some might be longer and some are broader.

We can use numbers to compare the sizes and weights of the fish.

Consider two fishes of which one is 20 and the other is 30

What does this mean?

20 is less than 30. Is the first fish is shorter than the second?

Or else is the first fish is lighter than the second?

Confusing right? This is because just by looking at the numbers...

....we cannot say if its talking about length or weight

Standard units of measurement are assigned to numbers to avoid confusion.

Standard units helps us to identify the characteristic of measurement

Let us look at standard units measurements.

To know the distance from one end of an object to other end of the object

We find the measurement of its length.

Standard units for measuring length are millimetres, centimetres....

..... metres, and kilometres.

Kilometre is the largest unit of length, followed by metres, centimetres.

Millimetres is the smallest unit of length.

In the two roads measuring 30 kilometres and 30 metres respectively.

We can say that the road of 30 kilometres is longer than the road measuring 30 metres.

To find how heavy an object is we find its weight.

Standard units for measuring weight are grams and kilograms

A fruit basket weighing 3 kilograms would be heavier than an apple weighing 30 grams.

Standard units of time are Hours, Minutes and Seconds

A Number 3 with units of measure as hours represent time of 3 hrs

Similarly, a number 50 with units of measure as minutes represent time of 50 minutes.

Revision

Standard units that indicate length are millimetres, centimetres, metres, and kilometres.

Standard units that indicate weight are kilograms and grams.

Standard units that indicate time are hours, minutes and seconds

The End