Decimals

Introduction and Summary

Decimals are everywhere, from price tags to Olympic scores. Thus, it is important to know what they mean and how to talk about them.

The first section will deal with place value for decimals, which is similar to place value for whole numbers, as described in Wholenumbers. This section will also talk about how to compare decimals. This is very important--it is often necessary (but confusing) to know which of two numbers with a decimal is larger. This section will eliminate some of the confusion.

The second section will explain how to round whole numbers and decimals. This skill is valuable because it is often easier to perform mental calculations on an approximation of a number, rather than on the actual number. Furthermore, in some cases it is only necessary to know an approximate answer. Rounding is also useful in measuring.

The final section will deal with computation using decimals. We will learn how to add, subtract, multiply, and divide decimals. It is crucial to know how to perform these four operations, since decimals will appear a great deal in both pre-algebra and higher mathematics.