**One percent of one billion is 10 million.** "Percent" is short for "per 100," so "one percent" is the same as "one per 100." To find one percent of any number, simply divide by 100.

Percentage is a ratio expressed as a fraction with 100 in the denominator. Fifty percent is the same as 50/100, which reduces to 1/2. In more complex calculations, percent value is found by finding the ratio and then multiplying by 100. For example, to find the percentage that 50 out of 1250 represents, divide 50 by 1250, which equals 0.04, then multiply by 100, so 50 is 4 percent of 1250.