Operation | Explanation | Example |
---|---|---|

Convert a decimal to a percent |
Move the decimal point 2 places to the right and add a percent (%) sign. If you need to, add a zero on the back to get the second decimal place. | .123 = 12.3% |

Convert a percent to a decimal |
Move the decimal point 2 places to the left. If you need to, put a zero on the front. | 5% = .05 |

Convert a fraction to a decimal |
Divide the numerator by the denominator, using your calculator. | 1/8 = .125 |

Convert a percent to a fraction |
First turn the number into a decimal. Then turn the number into a fraction by putting it over 10, 100, 1000, or whatever number is big enough to have enough zeroes for each place after the decimal. |
18% = .18 = 18/100 = 9/50 |

Memorize the common fractions, decimals and percents in this table | ||||||
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Fraction | Decimal | Percent | Fraction | Decimal | Percent | |

.25 | 25% |
.125 | ||||

.5 | 50% |
.25 | 25% |
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.75 | 75% |
.375 | 37.5% |
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.5 | 50% |
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.33333 | .625 | 62.5% |
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.66666 | .75 | 75% |
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.875 | 87.5% |
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.1 | 10% |
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.2 | 20% |
1.0 | 100% |
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.3 | 30% |
2.0 | 200% |