What is 7/9 of 87?

How to calculate 7/9 of 87?

1. Multiply the whole number by the numerator of the fraction: 87 × 7 = 609
2. Divide this result by denominator of the fraction: 609/9 = 67.666666666667
3. Simplify by dividing both the numerator and denominator by their GCD (3):
   • 609/3 = 203
   • 9/3 = 3
4. Which gives: 203/3

Since 203/3 is an improper fraction, the result could also be expressed as a mixed number: 67 2/3

How does it work?

The principle behind finding a fraction of a number, such as 7/9 of 87, is rooted in the method of cross-multiplication.

Consider the following proportion: $\frac{7}{9}=\frac{x}{87}$ (where x represents 7/9 of 87)

1. Using the cross-multiplication method, multiply both numerators by their opposite denominators: $7\times 87=9x$
2. Which gives: $609=9x$
3. Divide both sides by 9 to isolate x: $\frac{609}{9}=\frac{9x}{9}$
4. Which gives the result: $\frac{609}{9}=x$ (or $\frac{203}{3}=x$)

Thus, 7/9 of 87 is equal to 203/3 (or 67.666666666667 in its decimal form).