This QuickTime movie explains what ratios are and models how to solve a ratio problem. As you watch and listen to the teacher and students interact it helps clarify the thinking behind applying this concept. Click the start button to...

This QuickTime movie explains a solution to a word problem using subtraction. The teacher and student discuss how to work through it together to find a solution. As you watch and listen to them interact it helps clarify the thinking...

Learn about ratios by watching an Atlantean Dodgeball game! Ratio errors confuse one of the coaches as two teams face off in an epic dodgeball tournament. See how mathematical techniques such as tables, graphs, measurements, and...

Graphs of linear relationships are basically just lines and dots. In this video, you will learn the skills to understand and analyze the graphs to get useful information from them. [1:29]

This lesson is about solving real world problems that involve a combination of rates, proportions and percents. Also, it is aligned to a common core state standard CC.9-12.N.Q.2. [10:59]

Learn to convert hours, minutes, and seconds.

When you are asked to make an object bigger or smaller, you will ask, "by how much?". In this case, scale factor can help answer the question. In this lesson, we will practice how to enlarge and reduce objects according to the scale...

Carla's birthday cash is burning a hole in her pocket, but the stores downtown have her in a bind! Her favorite three stores all have sales - "Buy Two Get One Free," "40% off Everything," and "Buy One Get One Half Off." Which sale will...

Use what you know about percents, ratios, and proportions to figure out the sale price in this real world application of math. See if you can figure out how they calculated the correct price for the shoes Carla likes. Combining percents...

Somehow, a bank robber managed to infiltrate Mercenary Bank - and he's looking to fill a briefcase with a million dollars in stacks of 50 dollar bills. But is his briefcase large enough to hold a million bucks?

In this video (3:09), life-size replicas help demonstrate one-dimensional scaling and the ratio relationship between two real-world quantities. The accompanying classroom activity helps students understand how ratios and proportions can...

An introduction to multi-part ratios. [5:25]

In this lesson, students learn metric units for describing rates. It is 4 of 5 in the series titled "Metric Rates."

In this lesson, students see that ratios can consist of more than two terms. It is 4 of 10 in the series titled "Multiple Term Ratios."

In this lesson, students see that ratios can consist of more than two terms. It is 5 of 10 in the series titled "Multiple Term Ratios."

In this lesson, students see that ratios can consist of more than two terms. It is 1 of 10 in the series titled "Multiple Term Ratios."

This lesson demonstrates how to simplify ratios. It is 2 of 5 in the series titled "Simplifying Ratios."

This lesson demonstrates how to solve a proportion when a variable is present. It is 11 of 13 in the series titled "Solving a Proportion with an Unknown."

This lesson demonstrates how to solve a proportion when a variable is present. It is 13 of 13 in the series titled "Solving a Proportion with an Unknown."

This lesson demonstrates how to solve a proportion when a variable is present. It is 2 of 13 in the series titled "Solving a Proportion with an Unknown."

This lesson demonstrates how to solve a proportion when a variable is present. It is 4 of 13 in the series titled "Solving a Proportion with an Unknown."

This lesson demonstrates how to solve a proportion when a variable is present. It is 5 of 13 in the series titled "Solving a Proportion with an Unknown."

This lesson demonstrates how to solve a proportion when a variable is present. It is 7 of 13 in the series titled "Solving a Proportion with an Unknown."

This lesson demonstrates how to solve a proportion when a variable is present. It is 9 of 13 in the series titled "Solving a Proportion with an Unknown."