A decimal is a number with a decimal point and it includes a whole number part and a decimal part. 1.2, 1.8, 3.425 are examples of decimals.

Consider the following blocks, each of which is divided into 10 equal parts. Each one of these parts represents $\frac{1}{10}$ of the whole unit, the whole block.

Decimals

10 parts of Block 1 and 2 parts of Block 2 are shaded in red. In other words, 10 out of 10 parts are shaded in Block 1 and 2 out of 10 parts are shaded in Block 2. This is represented as 1.2 in decimal form, which means one whole and two-tenths of a whole. This can be written as 1.2 = 1 + $\frac{2}{10}$

A decimal number is a representation of a fraction and vice versa. Consider the number line. The unit length between 1 and 2 is divided into 10 equal parts. We take 8 parts as shown in the following figure.

What are Decimals

This point represents eight tenth more than one. We represent this as a decimal number, 1.8.
Here, 1.8 can be written as 1 + eight tenth
That is, 1.8 = 1 + $\frac{8}{10}$
We can see that a decimal number is a representation of a fraction and vice versa.

Examples on Decimals

Given below are some examples on decimals

Example 1:

3.245 is a decimal number where 3 is the whole number and 0.245 is the decimal part.
We can write 3.245 = 3 + two tenths + 4 hundredths + 5 thousandths

Example 2:

51. 9807 is a decimal number, where 51 represents the whole part and 0.9807 the decimal part.
51. 9807 = 51 + 9 tenths + 8 hundredths + 0 thousandths + 7 ten-thousandths
= 51 + 9 tenths + 8 hundredths + 7 ten- thousandths
If there is no whole number part, we write a 0 to the left of the decimal point. In the decimal number, 0. 234, there is no whole number part.

Example 3:

Write the fraction and decimal number representing the following figure.

Examples on Decimals

Here, a box is made of 10 equal parts and 7 of them are shaded in blue. We can represent this as $\frac{7}{10}$ as a fraction and 0.7 as the decimal point.