Integers can be stored easily in memory as binary numbers

However fractions are more complicated

Fixed point numbers are a simple way of storing fractional numbers in which the integer and fractional parts are stored in separate portions of the data structure.

each portion has a fixed size.

as opposed to floating point numbers in which the sizes are more dynamic.

Example

We want to store the number 15.5

We can use a two-byte fixed point number for this

The first byte is used to store the integer part: 15

This is just a case of converting it to binary and padding so we have 8 bits: 00001111

The second byte is used to store the fractional part: 0.5

This byte is divided into 256 separate units, each representing 1/256