7 R.1 Fractions, Decimals, and Percents Decimals as Fractions Converting a Decimal to a Fraction Read the decimal using the correct place value. Write it in fractional form just as it is read. • The numerator will be the digits to the right of the decimal point. • The denominator will be a power of 10—that is, 10 for tenths, 100 for hundredths, and so on. EXAMPLE 7 Writing Decimals as Fractions Write each decimal as a fraction. (Do not write in lowest terms.) (a) 0.95 (b) 0.056 (c) 4.2095 SOLUTION (a) We read 0.95 as “ninety-five hundredths.” 0.95 = 95 100 For hundredths (b) We read 0.056 as “fifty-six thousandths.” 0.056 = 56 1000 For thousandths (c) We read 4.2095, which is greater than 1, as “Four and two thousand ninety-five ten-thousandths.” 4 .2095 = 4 2095 10,000 Write the decimal number as a mixed number. = 42,095 10,000 Write the mixed number as an improper fraction. S Now Try Exercises 85, 89, and 91. Do not confuse 0.056 with 0.56, read “fifty-six hundredths,” which is the fraction 56 100. Think: 10,000 # 4 + 2095 Operations with Decimals EXAMPLE 8 Adding and Subtracting Decimals Add or subtract as indicated. (a) 6.92 + 14.8 + 3.217 (b) 47.6 - 32.509 SOLUTION (a) Place the digits of the decimal numbers in columns by place value. Attach zeros as placeholders. 6.92 6.920 14.8 becomes 14.800 + 3.217 + 3.217 24.937 Attach 0s. (b) 47.6 47.600 - 32.509 becomes - 32.509 15.091 Write the decimal numbers in columns, attaching 0s to 47.6. S Now Try Exercises 93 and 97. Be sure to line up decimal points. 6.92 is equivalent to 6.920. 14.8 is equivalent to 14.800.
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