Twenty percent of 100 is 20. To calculate the percentage of a number, convert the percentage to a decimal number; move the decimal point two places to the left, and multiply by the number. The word percent means per 100.
Know MoreWhile this example requires simple math, other problems involve more complex number manipulations. Percentages are also expressions of ratios, so 20 percent is also written as 20/100, a fraction that simplifies to 1/5.
While it is common to see the percent sign in science and math documents, writing style guides indicate using the word percent as their preference. Writing style guides also indicate that when a percent is not a whole number, the proper form is to write the number as a decimal rather than a mixed number.
Learn MoreDepending on the purity, a 10-ounce gold bar may contain between 106.3 (9-karat gold) and 283.5 (24-karat gold) grams of gold. The rest of the mass consists of less-valuable alloy metals such as copper or silver.
Full Answer >Forty percent is the same as 0.40 in decimal form. It is possible to convert a percentage to a decimal by moving the decimal point two places to the left.
Full Answer >The decimal form of 4.5 is .045 when 4.5 is a percentage. Understanding place values help identify the decimal form of a percentage.
Full Answer >The runoff coefficient is a term used to describe the fraction of total rainfall that is a part of the total runoff volume for a certain area of land. It can also be used to describe the ratio of the depth of the runoff to the depth of rainfall.
Full Answer >