What is 1/4 of 90?

How to calculate 1/4 of 90?

1. Multiply the whole number by the numerator of the fraction: 90 × 1 = 90
2. Divide this result by denominator of the fraction: 90/4 = 22.5
3. Simplify by dividing both the numerator and denominator by their GCD (2):
   • 90/2 = 45
   • 4/2 = 2
4. Which gives: 45/2

Since 45/2 is an improper fraction, the result could also be expressed as a mixed number: 22 1/2

How does it work?

The principle behind finding a fraction of a number, such as 1/4 of 90, is rooted in the method of cross-multiplication.

Consider the following proportion: $\frac{1}{4}=\frac{x}{90}$ (where x represents 1/4 of 90)

1. Using the cross-multiplication method, multiply both numerators by their opposite denominators: $1\times 90=4x$
2. Which gives: $90=4x$
3. Divide both sides by 4 to isolate x: $\frac{90}{4}=\frac{4x}{4}$
4. Which gives the result: $\frac{90}{4}=x$ (or $\frac{45}{2}=x$)

Thus, 1/4 of 90 is equal to 45/2 (or 22.5 in its decimal form).