It looks like you're using Internet Explorer 11 or older. This website works best with modern browsers such as the latest versions of Chrome, Firefox, Safari, and Edge. If you continue with this browser, you may see unexpected results.

Decimals are . . . -2.3, -.554, -.01, 1.9999998, 2.1, etc.

Decimal number basics

Place value and the decimal number system * *

Any study of decimal numbers must begin with a good understanding of place value. In this module, you can study the concept of place value and have an introduction to the decimal number system. Also included on this page are the concepts of expanded form and word form of decimal numbers.

Comparing and ordering decimals

In this module, you can study how to compare two decimal numbers to see which is larger and how to put a list of decimal numbers in order from least to greatest.

Rounding to a decimal place

In this module, you can study how to round numbers to a whole number place or to a decimal place.

Significant figures

In this module, you can study what a significant figure is and how to round to a significant figure.

Standard Form and Engineering Notation >

In this module, you can study two different ways to write very large and very small numbers in a format that makes them easier to use.

Calculating with decimal numbers

Adding decimals

In this module you can study how to add decimal numbers.

Subtracting decimals

In this module, you can study how to subtract decimal numbers.

Multiplying decimals

In this module, you can learn how to multiply two decimal numbers together.

Dividing decimals

In this module, you can study how to divide one decimal number by another.

Representing and ordering numbers

Converting decimals to fractions * *

In this module you can study how to convert a decimal number to a fraction.

Converting decimals to percents * ** *

In this module you can study how to convert a decimal number to a percent.

Converting between fractions, decimals and percents * *

In this module you can study how to convert between fractions, decimals and percents.

Ordering fractions, decimals and percents

In this module you can study how to put a list of fractions, decimals and percents in order from smallest to largest number.