In decimal we will discuss how to read and write decimal numbers.



The length of a pencil is 17.2 cm. This is read as seventeen point two cm.

Now, the decimal 49.50 can be converted into a fraction as:
49.50 = 4950/100

Similarly,

(i) 1.1 = 11/10

(ii) 2.13 = 213/100

(iii) 17.2 = 172/10

(iv)14.11 = 1411/100

(v) 9.781 = 9781/1000

So, we note that the number is divided:

(a) By 10 if there is one digit after the decimal.

(b) By 100 if there is two digits after the decimal.

(c) By 1000 if there is three digits after the decimal.

(a) The number is divided by 10 if there is one digit after the decimal.

For example:

(i) 1.5 = 15/10

[We observe that in 1.5, after the decimal there is one digit so we need to divide by 10]



(ii) 12.3 = 123/10

[We observe that in 12.3, after the decimal there is one digit so we need to divide by 10]



(iii) 10.1 = 101/10

[We observe that in 10.1, after the decimal there is one digit so we need to divide by 10]



(iv) 111.2 = 1112/10

[We observe that in 111.2, after the decimal there is one digit so we need to divide by 10]



(v) 145.9 = 1459/10

[We observe that in 145.9, after the decimal there is one digit so we need to divide by 10]



(b) The number is divided by 100 if there is two digits after the decimal.

For example:

(i) 2.51 = 251/100

[We observe that in 2.51, after the decimal there is two digits so we need to divide by 100]



(ii) 12.03 = 1203/100

[We observe that in 12.03, after the decimal there is two digits so we need to divide by 100]



(iii) 19.11 = 1911/100

[We observe that in 19.11, after the decimal there is two digits so we need to divide by 100]



(iv) 11.24 = 1124/100

[We observe that in 11.24, after the decimal there is two digits so we need to divide by 100]



(v) 14.93 = 1493/100

[We observe that in 14.93, after the decimal there is two digits so we need to divide by 100]



(c) The number is divided by 1000 if there is three digits after the decimal.

For example:

(i) 1.555 = 1555/1000

[We observe that in 1.555, after the decimal there is three digits so we need to divide by 1000]



(ii) 12.005 = 12005/1000

[We observe that in 12.005, after the decimal there is three digits so we need to divide by 1000]



(iii) 2.001 = 2001/1000

[We observe that in 2.001, after the decimal there is three digits so we need to divide by 1000]



(iv) 1.112 = 1112/1000

[We observe that in 1.112, after the decimal there is three digits so we need to divide by 1000]



(v) 15.913 = 15913/1000

[We observe that in 15.913, after the decimal there is three digits so we need to divide by 1000]