- Topics At a Glance
- Ratios & Proportions
- Unit Rate
- The Golden Ratio
- Solving Proportions
- Percents
- Working with Percents
- Percentage Increase & Decrease
- Percentages in the Real World
**Estimating Percentages**- Converting Decimals to Percents
- Converting Decimals to Fractions
- Converting Percents to Decimals
- Converting Percents to Fractions
- Converting Fractions to Decimals
- Converting Fractions to Percents
- Working with Percents, Fractions & Decimals

Most of the time in life, you will estimate percents. You probably won’t bust out a pen and paper every time you need to pay a tip or figure out the discount on a shirt. If you get good at *estimating* percents, you’ll get close enough.

The first thing to do is round the amount to a nice easy number to work with.

% | Trick | Round Amount | Estimate |
---|---|---|---|

10% | Move the decimal one place to the left | $72.38 -> $70.00 $58.20 -> $60.00 $26.00 -> $25.00 |
10% of $70.00 is $7.00 10% of $60.00 is $6.00 10% of $25.00 is $2.50 |

20% | Double 10% | $72.38 -> $70.00 $58.20 -> $60.00 $26.00 -> $25.00 |
20% of $75.00 is $15.00 20% of $60.00 is $12.00 20% of $25.00 is $5.00 |

25% | Round amount to a number divisible by 4, then divide the amount in fourths | $72.38 -> $72.00 $58.20 -> $60.00 $26.00 -> $28.00 | 25% of $72.00 is $18.00 25% of $60.00 is $15.00 25% of $28.00 is $7.00 |

50% | Cut the amount in half | $72.38 -> $72.00 $58.20 -> $60.00 $28.00 -> $28.00 | 50% of $72.00 is $36.00 50% of $60.00 is $30.00 50% of $28.00 is $14.00 |

Do the following problems in your head. Feel free to round the numbers.

Estimating Percentages Exercise 1

10% of $92.86

Estimating Percentages Exercise 2

50% of $131.90

Estimating Percentages Exercise 3

25% of $76.75

Estimating Percentages Exercise 4

20% of $14.09