What is Decimal Point?
It is a point or dot we use to separate the whole number part from the fractional part of a decimal number.
A decimal number is a number that consists of a whole number and a fractional part. The decimal point separates the whole number from the fractional part.
Example:
The decimal point is placed in between the ones and the tenths.
The whole number is written to the left of the decimal point. 
The fractional part is written to the right of the decimal point. 
So, a decimal number looks like:
The decimal point makes it easy to read a decimal number. We can read a decimal number in two ways:
1. Using “and” in place of the decimal point:
In this method:

The whole number part is read as is.

The decimal point is read as “and”.

Then the fractional part is read as is.
For example, the number 258.16 is read as “two hundred fiftyeight and sixteen hundredths”.
2. Reading the decimal point as “point”:
In this method:

The whole number part is read as is.

The decimal point is read as “point”.

Then the fractional part is read as individual digits.
For example, the number 258.16 is read as “two hundred fiftyeight point one six”.
Fun facts
