Examples of fractions equivalent to four-fifths are 8/10, 80/100, 16/20, 400/500 and 40/50. Fractions that are equivalent to four-fifths are those that can be reduced to four-fifths since four-fifths is already in the lowest terms. Fractions that are equivalent have the same value.

To find these equivalent fractions requires multiplying the top number, or numerator, and the bottom number, or denominator, by the same number. For instance, multiplying four by two makes the new numerator eight, and multiplying five by two makes the new denominator 10. The fraction 8/10 therefore is equivalent to four-fifths. Since 8/10 is written in decimal form as 0.8, the equivalent of four-fifths in decimal form is also 0.8