Читать книгу Algebra I All-in-One For Dummies - Mary Jane Sterling, Mary Sterling Jane - Страница 94

When a decimal repeats itself, you can always find the fraction that corresponds to the decimal. In this chapter, I only cover the decimals that show every digit repeating.

To change a repeating decimal (in which every digit is part of the repeated pattern) into its corresponding fraction, write the repeating digits in the numerator of a fraction and, in the denominator, as many 9’s as there are repeating digits. Reduce the fraction if necessary.

Q. Write the decimal as a fraction in lowest terms.

A. . The three repeating digits are 126. Placing the 126 over a number with three 9’s, you reduce by dividing the numerator and denominator by 9.

Q. Write the decimal as a fraction in lowest terms.

A. The six repeating digits are put over six 9’s. Reducing the fraction takes a few divisions. The common factors of the numerator and denominator are 11, 13, 27, and 37. When completely reduced, you have .

44 Change to a decimal.

45 Change to a decimal.

46 Change to a decimal.

47 Change 0.45 to a fraction.

48 Change to a fraction.

49 Change to a fraction.

50 Round the decimal 4.172797 to the nearest thousandth.