What is 1/2 of 40?

How to calculate 1/2 of 40?

1. Multiply the whole number by the numerator of the fraction: 40 × 1 = 40
2. Divide this result by denominator of the fraction: 40/2 = 20
3. Simplify by dividing both the numerator and denominator by their GCD (2):
   • 40/2 = 20
   • 2/2 = 1
4. Which gives: 20/1

How does it work?

The principle behind finding a fraction of a number, such as 1/2 of 40, is rooted in the method of cross-multiplication.

Consider the following proportion: $\frac{1}{2}=\frac{x}{40}$ (where x represents 1/2 of 40)

1. Using the cross-multiplication method, multiply both numerators by their opposite denominators: $1\times 40=2x$
2. Which gives: $40=2x$
3. Divide both sides by 2 to isolate x: $\frac{40}{2}=\frac{2x}{2}$
4. Which gives the result: $\frac{40}{2}=x$ (or $\frac{20}{1}=x$)

Thus, 1/2 of 40 is equal to 20/1 (or 20 in its decimal form).