130 likes | 278 Views
Percentages. or Fractions Disguised by a Latin Name. A short review…. Per Something. “per something” means “divided by something” Such as $3.25 per gallon , or $.99 per pound , or 25 miles per hour , or 8 ¢ per kilowatt-hour , and can be expressed as. Latin per cent.
E N D
Percentages or Fractions Disguised by a Latin Name epw 10/9/06
A short review… epw 10/9/06
Per Something • “per something” means • “divided by something” • Such as $3.25 per gallon, or • $.99 per pound, or • 25 miles per hour, or • 8¢per kilowatt-hour, and can be expressed as epw 10/9/06
Latin per cent • per cent means “per one hundred” • which is “divided by 100” • We use the symbol % as a shorthand for the words per cent • We read 50% as “50 percent” and it means epw 10/9/06
The Big P • For a number P epw 10/9/06
Examples epw 10/9/06
Examples (cont.) = 15 epw 10/9/06
Conversions(those pesky conversions, again! ) • Percentage to a common fraction • Replace % symbol with division by 100 • Simplify the fraction if necessary epw 10/9/06
Conversions (cont.) • Convert a percentage to a decimal • Drop the % symbol and move the decimal point two places to the left epw 10/9/06
Conversions (cont.) • Convert a decimal to a percentage • Move the decimal point two places to the right (adding a zero if necessary), and • Add the % symbol 0.43 = 43% 0.7 = 70% 0.0043 = 0.43% epw 10/9/06
Conversions (cont.) • Convert a common fraction to a percentage • Convert the fraction to decimal form, then • Convert the decimal to a percentage epw 10/9/06
The End! epw 10/9/06