Simplifying 21/9

How to reduce 21/9 to its simplest form

To simplify 21/9 we have to divide both numerator (21) and denominator (9) by their greatest common factor (GCF). In other words, writing a fraction in its simplest form means that both numerator and denominator can no longer be divided by the same whole number other than 1.

Result simplifying 21/9

Greatest Common Factor (GCF): 3

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Simplifying 21/9 step by step

Find the greatest common factor of 21 and 9

To simplify a fraction, look for the greatest common factor of the numerator and the denominator. The greatest common divisor of 21 and the 9 is 3. We therefore divide the numerator and denominator by 3.

21 / 3

9 / 3

If your fraction is improper, simplify it as a mixed number.

An improper fraction is a fraction that has a larger numerator than denominator. To simplify an improper fraction as a mixed number (a number that combines a whole number and a fraction) you have to determine how many times the denominator fits the numerator. In this case the denominator (3) fits the numerator (7) 2 times. The leaves us with a remainder of 1. Therefore we can rewrite the fraction like this:

(2 x 3) + 1

Simplify fractions

If a fraction is not yet in its simplest form, you can rewrite (reduce) it into a fraction where numerator and denominator are as small as possible. Try our simplified fraction calculator to simplify your fractions and find the greatest common factor (GCF).

Simplify fraction calculator

A fraction is irreducible (in its simplest form) when the numerator and denominator have no common factors other than 1. In that case the greatest common factor is 1.