Chapter 3

Working with Fractions and Decimals

Fractions and decimals are closely related. A fraction can be expressed as either a repeating or terminating decimal. A decimal is a special type of fraction — it always has a denominator that's some power of ten. Decimal numbers are often written with a lead zero. You'll see 0.031 instead of .031. The lead zero helps keep the decimal point from getting overlooked.

The Problems You'll Work On

In this chapter, you'll work with fractions and decimals in the following ways:

  • Adding and subtracting fractions by finding a common denominator
  • Multiplying and dividing fractions by changing to improper fractions and reducing where possible
  • Simplifying complex fractions
  • Adding and subtracting decimals by aligning decimal points
  • Multiplying decimals by assigning the decimal place last
  • Dividing decimals by assigning the decimal place first
  • Changing fractions to decimals — repeating or terminating
  • Changing decimals to fractions and then reducing
  • Rounding decimals to designated places

What to Watch Out For

Don't let common mistakes trip you up; remember the following when working with fractions and decimals:

  • Finding the least common denominator of fractions before adding or subtracting
  • Recognizing the numerators and denominators in the numerator and denominator of a complex fraction
  • Reducing fractions correctly by dividing by factors, not terms
  • Recognizing the correct decimal place when rounding

Adding and Subtracting Fractions

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