PBS
The Lowdown — Exploring Changing Obesity Rates through Ratios and Graphs
Math and medicine go hand-in-hand. After viewing several infographics on historical adult obesity rates, pupils consider how they have changed over time. They then use percentages to create a new graph and write a list of questions the...
Illustrative Mathematics
Overlapping Squares
The objective of this activity is to find the percent of the area of a two squares overlapping. Mathematicians find the ratio of area for the part that overlaps to the rectangle formed. The final answer is a percent as a rate per 100....
PBS
Soul Food Junkies: Portions
Serve up a rate of percents. The Math at the Core resource investigates the percent of daily value of sodium and saturated fats in different foods. Pupils determine the number of serving sizes they eat of popular snack foods and...
Illustrative Mathematics
Gotham City Taxis
Taxi! Have your travelers figure out how far they can go in a taxi for $10.00. They must account for the mileage rate and tip in their calculation. They can set up a table or make an equation to solve for the exact mileage they can...
Illustrative Mathematics
Tax and Tip
Finding out how to calculate tax and tip is a valuable skill that all young adults should be able to do without a calculator. Learners are given a bill and asked to calculate the tax, tip, and total amount. Calculations can be exact or...
Curated OER
Task: Range of Motion
If you have ever injured your shoulder, you know it takes a while to improve your arm's range of motion. In this real-world example, young mathematicians gain insight into the world of physical therapy while they analyze a case study...
Illustrative Mathematics
Anna in D.C.
The amount of tax and tip on a restaurant bill is a common example used in percent problems. Here, learners only know the total amount paid, and they need to figure the itemized amounts. Solutions using a ratio table, using knowledge of...
Curated OER
Task: Grain Storage
Farming is full of mathematics, and it provides numerous real-world examples for young mathematicians to study. Here, we look at a cylinder-shaped storage silo that has one flat side. Given certain dimensions, students need to determine...
Lawrence Hall of Science
The Math Page: Skill in Arithmetic: Percents Are Ratios
This Math Page tutorial explains how percents are ratios and then features a practice exercise.
The Math League
The Math League: Ratio and Proportion
This tutorial provides definitions and examples of ratios and proportions and features comparing ratios and converting rates.
National Council of Teachers of Mathematics
The Math Forum: Calculating Sales Tax
Dr. Math is asked about calculating sales tax. A quick and easy to follow explanation of how it works using fractions, decimals, ratio, and percent.