What is 4/10 of 54?

How to calculate 4/10 of 54?

1. Multiply the whole number by the numerator of the fraction: 54 × 4 = 216
2. Divide this result by denominator of the fraction: 216/10 = 21.6
3. Simplify by dividing both the numerator and denominator by their GCD (2):
   • 216/2 = 108
   • 10/2 = 5
4. Which gives: 108/5

Since 108/5 is an improper fraction, the result could also be expressed as a mixed number: 21 3/5

How does it work?

The principle behind finding a fraction of a number, such as 4/10 of 54, is rooted in the method of cross-multiplication.

Consider the following proportion: $\frac{4}{10}=\frac{x}{54}$ (where x represents 4/10 of 54)

1. Using the cross-multiplication method, multiply both numerators by their opposite denominators: $4\times 54=10x$
2. Which gives: $216=10x$
3. Divide both sides by 10 to isolate x: $\frac{216}{10}=\frac{10x}{10}$
4. Which gives the result: $\frac{216}{10}=x$ (or $\frac{108}{5}=x$)

Thus, 4/10 of 54 is equal to 108/5 (or 21.6 in its decimal form).