# Ratios & Percentages Topics

#### Ratios & Proportions

Many people use the terms "ratio" and "proportion" as though they mean the same thing, but (red alert!) they do not mean the same thing. Ratios compare one part to a different partProportions...

#### Unit Rate

Unit rate is the ratio of cost: number of units. Then the ratio is simplified so that the number of units is 1.Having a knack for unit rates can make you a smarter shopper. For example, let's...

#### The Golden Ratio

The golden ratio is the most beautiful number you may ever see. We know that sounds a little over the top, but really, everything looks better when the golden ratio is applied. Architects, pai...

#### Solving Proportions

When solving a problem that has a ratio, proportions are often a lot easier to work with. There are a few ways to solve these problems.
Method 1: cross multiplication. This is where you’l...

#### Percents

A percent is just a fraction with a nice, easy denominator of 100. You see percents everywhere: shopping, grades, weather forecasts, sports statistics. Like fractions and decimals, percentages...

#### Working with Percents

In this section we will solve each percentage problem using two different methods. After you try the two methods, take your pick of which one works best for you. It’s your call, boss.Method 1:...

#### Percentage Increase & Decrease

When an item goes on sale, or rises in price, this is often referred to as a percent decrease or increase. This isn't anything new, no new processes to learn or rules to memorize. Basically,...

#### Percentages in the Real World

You will use percents for the rest of your life. That's a promise, not a threat.Check out the examples for just a few places where percents will cross your path: commission, discounts, sales t...

#### Estimating Percentages

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 est...

#### Converting Decimals to Percents

Here you see seven tenths. If we divide each of those tenths into ten parts, we get seventy hundredths. Since all percents are out of 100, this is 70%.This one is super easy. All you really need...

#### Converting Decimals to Fractions

Above you will see forty-five hundredths, which means forty-five out of a hundred. If you reduce that fraction you get 9/20.When converting a decimal to a fraction, all you really need to do is...

#### Converting Percents to Decimals

To convert a percent to a decimal, you do the opposite of converting a decimal into a percent; instead of multiplying by 100, divide by one hundred. You can also simply move the decimal two pla...

#### Converting Percents to Fractions

Twenty-five percent means twenty-five out of one hundred. When you reduce that fraction, it simplifies to .To convert a percent to a fraction, place the percent number over 100, and reduce the...

#### Converting Fractions to Decimals

Eight twenty-fifths is equivalent to thirty-two hundredths (i.e., multiply both the numerator and denominator by 4 (that is, 4/4 or 1). You will get 32/100.). Thirty-two hundredths can be wri...

#### Converting Fractions to Percents

Two fifths is equivalent to forty hundredths, and because all percents are out of a hundred, this can be written as 40%.Just as with converting fractions to decimals, this technique doesn't alw...

#### Working with Percents, Fractions & Decimals

Working with Percents, Fractions & DecimalsYou will often find two or more of these forms mixed together in a sentence or a math problem. Don't sweat. Just convert! Use whatever form is...