What is 4/10 of 28?

How to calculate 4/10 of 28?

1. Multiply the whole number by the numerator of the fraction: 28 × 4 = 112
2. Divide this result by denominator of the fraction: 112/10 = 11.2
3. Simplify by dividing both the numerator and denominator by their GCD (2):
   • 112/2 = 56
   • 10/2 = 5
4. Which gives: 56/5

Since 56/5 is an improper fraction, the result could also be expressed as a mixed number: 11 1/5

How does it work?

The principle behind finding a fraction of a number, such as 4/10 of 28, is rooted in the method of cross-multiplication.

Consider the following proportion: $\frac{4}{10}=\frac{x}{28}$ (where x represents 4/10 of 28)

1. Using the cross-multiplication method, multiply both numerators by their opposite denominators: $4\times 28=10x$
2. Which gives: $112=10x$
3. Divide both sides by 10 to isolate x: $\frac{112}{10}=\frac{10x}{10}$
4. Which gives the result: $\frac{112}{10}=x$ (or $\frac{56}{5}=x$)

Thus, 4/10 of 28 is equal to 56/5 (or 11.2 in its decimal form).