The mixed number 21 89/20 written as an improper fraction is 509/20
To turn the mixed number 21 89/20 into an improper fraction, use these simple steps:
First, multiply the whole number by the denominator of the fractional part: 21 × 20 = 420.
After that, add the result to the numerator of the fractional part: 420 + 89 = 509.
Next, Write the sum of the previous step on the original denominator: 509/20.
This means that 21 89/20, as an improper fraction, equals 509/20.
See also: 21 89/20 as a decimal