In order to express a number as a percentage, one converts it from a mixed number or fraction to a decimal, moves the decimal point two places to the right and adds the percent sign. By definition, percentage is the rate per 100. Moving the decimal point is a shortcut for multiplying by 100.
Know MoreWhen using percentages in calculations, it is easiest to convert the number back to a decimal before completing the operation. The conversion involves moving the decimal point two places to the left and removing the decimal. To calculate a percentage of a total, multiply the total by the resulting decimal number. Unless the percentage is greater than 100, the resulting number is always smaller than the total.
Percentages are useful in daily life. When dining out, the guideline for tipping is 18 to 20 percent of the total bill. People can calculate a 20 percent tip by multiplying the total of the bill by 0.20. They can also adjust the amount of the tip to compensate for service received. Tax rates also use percentages. Shoppers can calculate a sales tax rate of 6 percent by multiplying the total by 0.06. The consumer pays an additional six cents for every dollar he spends.
The use of percentages converts portions to whole numbers. Scientists often deal with ratios that are too small to report as a rate per 100. They use parts per million or parts per billion in a similar way to that in which percentages are used.
Learn more about Fractions & PercentagesA whole number and a mixed number are simplified by first expressing the sum as a fraction with the same denominator as the proper fraction portion of the mixed number, and then simplifying that fraction if possible. The resulting number is an improper fraction. To convert the improper fraction to a ratio such as x:y, write the numerator of the fraction before the colon, with the denominator after.
Full Answer >To convert a mixed number to its lowest form, one needs to change the mixed number into an improper fraction and then reduce this improper fraction to the lowest possible fraction. To do these conversions, one needs to perform a few calculations. One also has to understand the definitions of "mixed number," "improper fraction" and "proper fraction."
Full Answer >To change an improper fraction into a mixed number, divide the numerator by the denominator and use the resulting quotient, remainder and divisor as the whole numeral, numerator and denominator, respectively. The mixed number makes clear how many complete wholes and fractional parts are present.
Full Answer >Convert a fraction to a decimal by first converting mixed numbers to improper fractions and then dividing the numerator by the denominator. Round the answer to the appropriate number of significant figures. The time to complete the process depends on the student's math skills and the use of a calculator.
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