What is 2/3 of 21?

How to calculate 2/3 of 21?

1. Multiply the whole number by the numerator of the fraction: 21 × 2 = 42
2. Divide this result by denominator of the fraction: 42/3 = 14
3. Simplify by dividing both the numerator and denominator by their GCD (3):
   • 42/3 = 14
   • 3/3 = 1
4. Which gives: 14/1

How does it work?

The principle behind finding a fraction of a number, such as 2/3 of 21, is rooted in the method of cross-multiplication.

Consider the following proportion: $\frac{2}{3}=\frac{x}{21}$ (where x represents 2/3 of 21)

1. Using the cross-multiplication method, multiply both numerators by their opposite denominators: $2\times 21=3x$
2. Which gives: $42=3x$
3. Divide both sides by 3 to isolate x: $\frac{42}{3}=\frac{3x}{3}$
4. Which gives the result: $\frac{42}{3}=x$ (or $\frac{14}{1}=x$)

Thus, 2/3 of 21 is equal to 14/1 (or 14 in its decimal form).