What is 9/6 of 81?

How to calculate 9/6 of 81?

1. Multiply the whole number by the numerator of the fraction: 81 × 9 = 729
2. Divide this result by denominator of the fraction: 729/6 = 121.5
3. Simplify by dividing both the numerator and denominator by their GCD (3):
   • 729/3 = 243
   • 6/3 = 2
4. Which gives: 243/2

Since 243/2 is an improper fraction, the result could also be expressed as a mixed number: 121 1/2

How does it work?

The principle behind finding a fraction of a number, such as 9/6 of 81, is rooted in the method of cross-multiplication.

Consider the following proportion: $\frac{9}{6}=\frac{x}{81}$ (where x represents 9/6 of 81)

1. Using the cross-multiplication method, multiply both numerators by their opposite denominators: $9\times 81=6x$
2. Which gives: $729=6x$
3. Divide both sides by 6 to isolate x: $\frac{729}{6}=\frac{6x}{6}$
4. Which gives the result: $\frac{729}{6}=x$ (or $\frac{243}{2}=x$)

Thus, 9/6 of 81 is equal to 243/2 (or 121.5 in its decimal form).