A decimal number is any number made up of the digits ... You can use a place value chart to help see the value of each digit in a number. Let's put the number 258.35 into a place value ...
A decimal is a way of writing a number that is not whole. Decimal numbers are 'in between' numbers. For example, 10.4 is in between the numbers 10 and 11. It is more than 10, but less than 11.