Lesson 1 Naming Decimals 
Decimal numbers, like fractions, allow us to express fractional parts of a number—including places between the integer values on the number line.
In the example shown below, you can see two different points (shown in blue) on a number line that do not fall directly on the integer values. One of the values in this example is between –3 and –2, and the other is somewhere between +2 and +3.
Decimal numbers can be located between the integer values on a number line.
Definition There are three parts to a decimal number:
A decimal consists of an integer and a decimal fraction, separated by a decimal point.

Decimal fractions play the same roles in mathematics as the numeratoranddenominator fractions that you have already studied in these lessons. However, you will soon discover that decimal fractions are much more useful and far easier to work with.
This counter runs continuously from decimal value 1.00 to 9.99. 
Naming Decimal Place Values
Just as whole numbers and integers have place values, so do decimal numbers. A Decimal number has three parts, including a wholenumber part. And, just as before, the wholenumber part has place values called tens, hundreds, thousands, and so on. But the decimal fraction part is different.
In a decimal number, the decimal point is the starting point for determining place values. Place value on the left side of the decimal point are the wholenumber values. Place values on the right side of the decimal point are the decimalfraction place values.
NOTE There is no equivalent of a 1's place in the fraction part of a decimal number. There is a 1's place in the wholenumber part, but not in the decimal part. 
Examples
Use these interactive examples and exercises to strengthen your understanding and build your skills.
If you are having any trouble understanding the content of this lesson, you will benefit from a more detailed tutorial on the subject. 