Decimal Representation Math Example 1

Follow the full solution, then compare it with the other examples linked below.

Example 1

easy
Convert 58\dfrac{5}{8} to a decimal by long division, and determine whether it terminates or repeats.

Solution

  1. 1
    Divide 5รท85 \div 8: 88 goes into 5050 six times (4848), remainder 22. So far: 0.60.6.
  2. 2
    88 goes into 2020 twice (1616), remainder 44. Decimal: 0.620.62.
  3. 3
    88 goes into 4040 five times (4040), remainder 00. Decimal: 0.6250.625.
  4. 4
    Remainder is 00, so the decimal terminates: 58=0.625\dfrac{5}{8} = 0.625.

Answer

58=0.625\dfrac{5}{8} = 0.625 (terminating decimal)
A fraction in lowest terms terminates as a decimal if and only if its denominator has no prime factors other than 22 and 55. Here 8=238 = 2^3, so the decimal terminates.

About Decimal Representation

Writing fractions as digits to the right of a decimal point, using place values of tenths, hundredths, thousandths, etc.

Learn more about Decimal Representation โ†’

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