Ratios & Percentages Topics


Ratios & Proportions

RatiosOne thing most people overlook when planning to move to a new town is figuring out how many dangerous creatures live there. We won't make the same mistake, and luckily we have ratios to help...

Unit Rate

A rate is a ratio of two numbers measured in different units. A unit rate is a rate that's been simplified so that one of the numbers of units is 1. Unit rates make life easier. For example, if a...

The Golden Ratio

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

Solving Proportions

A proportion is two equal ratios. If we know that two ratios are equal and we only know one of them, we can use it to hunt down the other one. Proportions, or equal ratios, are super convenient for...

Scale Models & Similarity

Scale ModelsMini-Me is a clone, identical in every way to Dr. Evil, except that he's his size. The ratio or 1:8 means that for every 1 inch of Mini-Me, there are 8 inches of pure Dr. Evil. This r...

Percents

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

Converting Decimals to Percents

Percents, decimals, and fractions all represent parts of a whole, so we can totally convert between 'em. First on the agenda is converting decimals to percents.Here we see seven tenths, or 0.7. If...

Converting Percents to Decimals

To convert a percent to a decimal, we do the opposite of converting a decimal into a percent; instead of multiplying by 100, divide by 100. We can also simply move the decimal point two places t...

Converting Decimals to Fractions

Up top we see forty-five hundredths, which means 45 out of 100. If we reduce that fraction, we get .When converting a decimal to a fraction, all we really need to do is look at the last place value...

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 twenty-fifths is equivalent to thirty-two hundredths. All we did was multiply the top and bottom of t...

Converting Fractions to Percents

Next up on this crazy conversion train: transforming fractions into percents. If a fraction can be written with a denominator of 100, converting it to a percent is easy peasy. Take a gander at the...

Converting Percents to Fractions

We've got one more conversion trick for ya: zapping percents into fractions. 25% means 25 out of 100. When we reduce that fraction, it simplifies to . Like we can see in the image above, 25% is the...

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 problem? That's like comparing apples and oranges and dragonfruits, isn't it?Don't sweat it. Just use...

Working with Percentages

What if we're asked something like, "What is 15% of 72?" Percentages are out of 100, but, uh, our total here is 72, not 100. Don't worry. We've got your back.In this section, we'll show two differe...

Percent Increase & Decrease

When an item goes on sale, or rises in price, it goes up or down by a certain percentage. This percentage is often referred to as a percent decrease or increase. Flashing lights, blaring siren: war...

Percentages in the Real World

You'll use percentages for the rest of your life. That's a promise, not a threat. Percentages are used to figure out how much money we need to put 10% down on an apartment, how much we'll pay f...

Estimating Percentages

Honestly, 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 fir...