1. Percents, Decimals, and Fractions
Chapter 1 / Whole Numbers and Introduction to Algebra
Section 6.2
Percents, Decimals, and Fractions

2. Chapter 1 / Whole Numbers and Introduction to Algebra
Understanding Percent
The word percent comes from the Latin phrase per centum, which means “per 100.”
Percent means per one hundred. The “%” symbol is used to denote percent.
1% = = 0.01
Martin-Gay, Prealgebra & Introductory Algebra, 2ed

3. Chapter 1 / Whole Numbers and Introduction to Algebra
Writing a Percent as a Decimal
Replace the percent symbol with its decimal equivalent, 0.01; then multiply.
43% = 43(0.01) = 0.43
100% = 100(0.01) = 1.00 or 1
Martin-Gay, Prealgebra & Introductory Algebra, 2ed

4. Chapter 1 / Whole Numbers and Introduction to Algebra
Writing a Decimal as a Percent
Multiply by 1 in the form of 100%.
0.65 = 0.65(100%) = 65.% or 65%
Martin-Gay, Prealgebra & Introductory Algebra, 2ed

5. Chapter 1 / Whole Numbers and Introduction to Algebra
Writing a Percent as a Fraction
Replace the percent symbol with its fraction equivalent, ; then
multiply. Don’t forget to simplify the fraction, if possible.
43% = =
Martin-Gay, Prealgebra & Introductory Algebra, 2ed

6. Chapter 1 / Whole Numbers and Introduction to Algebra
Writing a Fraction as a Percent
Multiply by 1 in the form of 100%.
Martin-Gay, Prealgebra & Introductory Algebra, 2ed

7. Chapter 1 / Whole Numbers and Introduction to Algebra
Helpful Hint
We know that
100% = 1
Recall that when we multiply a number by 1, we are not changing the value of that number.
Therefore, when we multiply a number by 100%, we are not changing its value but rather writing the number as an equivalent percent.
Martin-Gay, Prealgebra & Introductory Algebra, 2ed

8. Chapter 1 / Whole Numbers and Introduction to Algebra
Summary of Converting Percents, Decimals, and Fractions
To write a percent as a decimal, replace the % symbol with its decimal equivalent, 0.01; then multiply.
To write a percent as a fraction, replace the % symbol with its fraction equivalent, ; then multiply.
To write a decimal or fraction as a percent, multiply by 100%.
Martin-Gay, Prealgebra & Introductory Algebra, 2ed