Study Guide

Ratios & Percentages Topics

Ratios & Proportions

One thing most people overlook when planning to move to a new town is figuring out how many...

Unit Rate

A rate is a ratio of two numbers measured in different units. A unit rate is a rate that's been...

The Golden Ratio

The golden ratio is the most beautiful number we may ever see. We know that sounds a little over...

Solving Proportions

A proportion is two equal ratios. If we know that two ratios are equal and we only know one of...

Scale Models & Similarity

Mini-Me is a clone, identical in every way to Dr. Evil, except that he's his size. The ratio or...

Percents

A percent is just a fraction or ratio with a nice, easy denominator of 100.We see percents...

Converting Decimals to Percents

Percents, decimals, and fractions all represent parts of a whole, so we can totally convert...

Converting Percents to Decimals

To convert a percent to a decimal, we do the opposite of converting a decimal into a percent;...

Converting Decimals to Fractions

Up top we see forty-five hundredths, which means 45 out of 100. If we reduce that fraction, we...

Converting Fractions to Decimals

How do we go from a fraction to a decimal? We're so glad you asked.Like we can see above, eight...

Converting Fractions to Percents

Next up on this crazy conversion train: transforming fractions into percents. If a fraction can...

Converting Percents to Fractions

We've got one more conversion trick for ya: zapping percents into fractions. 25% means 25 out of...

Comparing Percents, Fractions, & Decimals

What should we do if we find two or more of these forms mixed together in a sentence or a math...

Working with Percentages

What if we're asked something like, "What is 15% of 72?" Percentages are out of 100, but, uh, our...

Percent Increase & Decrease

When an item goes on sale, or rises in price, it goes up or down by a certain percentage. This...

Percentages in the Real World

To figure this one out, we just need to add the 9.25% sales tax to the total. First find 9.25% of...

Estimating Percentages

Honestly, you probably won't bust out a pen and paper every time you need to pay a tip or figure...