Study Guide

# Ratios & Percentages Introduction

## Ratios & Percentages Introduction

Ratios, proportions, and percentages are all about comparing and measuring stuff. They can help us measure popularity, or find how rare something might be, or figure out a discount at our favorite store.

A ratio compares any two numbers, like the number of students who can do standing backflips to the number of students who can't. A proportion compares two equivalent ratios. A percentage compares any number to a total out of 100, like the number of corkscrew flips we landed out of 100 tries.

Whew. We're getting dizzy.

## Ratios & Percentages Resources

Concentration
This classic memory game matches percents to fractions.

Comparing Fractions and Percents
The title says it all: this set of videos shows you how to match up fractions with their percentage alter-egos.

Fraction-Percent Balance Scale
This scale allows you to balance percents and fractions. It's a nice way to compare the two.

Free Ride
Use bicycle gears to explore relationships between two gears.

Galactic Exchange
Use ratios to determine how much each coin is worth. Get a pen and paper ready.

Scale Factor
Use this scale tool to explore relationships between length, area, and perimeter.

The Golden Ratio
This page explores everything you need to know about the golden ratio and how it shows up in nature, architecture, and even cartoons.

Leonardo da Vinci Activity
This activity explores ratios and how they're used in drawing. Is your arm span really the same as your height? Find out!

Penguin Waiter Percent Game
This site offers a variety of word problems involving tipping your waiter. Who is a penguin, obviously.

Fraction Maker!
It makes fractions! And percents and decimals, too. This is a handy tool that shows what various fractions, decimals, and percents look like visually.