Curated OER
How Do You Find the Rate of Change Between Two Points on a Graph?
The instructor uses a graph representing time and distance to illustrate how to solve this word problem. She explains each step: rate of change, distance, time, vertical change over horizontal change, change in distance, and change in...
Curated OER
Why is it Called a Rational Expression?
If your algebraic expression is a ratio of two polynomials then you have a rational expression. Find out what that might look like.
Curated OER
What's a Rational Expression?
A rational expression has a polynomial in the numerator as well as a polynomial in the denominator. The instructor writes out an example for you to see.
Government of Alberta
Learn alberta.ca: Math Interactives: Rate/ratio/proportion (Video Interactive)
The use of rate, ratio, and proportion is illustrated in this video about action photography. An additional interactive element allows students to explore equivalent ratios equivalencies through enlarging and reducing images to compare...
Khan Academy
Khan Academy: Algebra: More Advanced Ratio Problem With Algebra
A step-by-step instructional video on how to solve a ratio problem using algebra. [9:58]
Khan Academy
Khan Academy: Algebra: Alternate Solution to Ratio Problem
A step-by-step demonstration on an alternate method for how to solve a ratio problem algebraically with cross multiplication. [7:02]
Khan Academy
Khan Academy: Arithmetic and Pre Algebra: Find an Unknown in a Proportion 2
This video shows how to find an unknown quantity in a proportion in the context of a word problem. Practice problems are available. [5:48]
Khan Academy
Khan Academy: Arithmetic and Pre Algebra: Introduction to Ratios
This video introduces and explains the concept of ratios through a number of examples. Practice problems are available. [14:13]
Khan Academy
Khan Academy: Algebra: Ratio Problems With Basic Algebra
A step-by-step breakdown on how to solve ratio problems using algebra. Practice problems available. [5:12]
Khan Academy
Khan Academy: Arithmetic and Pre Algebra: Understanding Proportions
This video showing how to determine if a given proportion is true or false. Practice problems are available. [1:25]
Khan Academy
Khan Academy: Algebra: Ratio and Proportion
Step-by-step instructions on how to solve ratio and proportion word problems. This video is also found in the strand Algebra: ck12.org. [10:25]
Khan Academy
Khan Academy: Algebra: Finding Unit Prices
A short video with an explanation on how to find a unit price from a real-world application problem. This video also appears in the strand Arithmetic and Pre-Algebra: Ratios and Proportions. [2:01]
Khan Academy
Khan Academy: Arithmetic and Pre Algebra: Finding Unit Rates
This video shows how to find a unit rate in the context of a word problem. Practice problems are available. [2:31]
Khan Academy
Khan Academy: Algebra: Ratios as Fractions in Simplest Form
Short video demonstrating how to write a ratio as a fraction in the simplest form by finding the greatest common factor. This video also appears in the strand Arithmetic and Pre-Algebra: Ratios and Proportions. [1:19]
Khan Academy
Khan Academy: Arithmetic and Pre Algebra: Finding Unit Prices
This video shows how to find a unit price in the context of a word problem and write it in simplest form. Practice problems are available. [2:01]
Khan Academy
Khan Academy: Arithmetic and Pre Algebra: Ratios as Fractions in Simplest Form
This video shows how to write a ratio as a fraction in simplest form. Practice problems are available. [1:19]
PBS
Pbs Learning Media: Real Life Math: Woodworker
Listen to a master craftsman explain many of the ways that mathematics is used in woodworking, including number operations; geometry; ratios and proportions; and measurement. In the accompanying activity, students will draw a scale...
PBS
Pbs Learning Media: I <3 Math: Percent as a Rate
This "I <3 Math" episode uses real-world comparisons to convert rates into equivalent percentages.
PBS
Pbs Learning Media: I <3 Math: Unit Rates
This "I <3 Math" episode defines unit rates and discusses their relationship to ratios. [2:01]
PBS
Pbs Learning Media: I <3 Math: What Is a Ratio?
This video is an introduction to the concept of ratios that provides real-world examples. This "I <3 Math" episode defines ratios, discusses combining ratios, and demonstrates the correct ways to write ratios. [2:37]
PBS
Pbs Learning Media: I <3 Math
This video series introduces key Common Core concepts in 4th-8th grade mathematics. Each video focuses on building a conceptual understanding of a topic so that students understand the "how" and "why" behind mathematical problem-solving.
PBS
Pbs Learning Media: Math in Fencing: Distance as a Variable
Learn how understanding distance--both lunge distance and the distance between you and your opponent--is an important strategy in the art of fencing. This clip is from the Center for Asian American Media. In the accompanying classroom...
PBS
Pbs Learning Media: Math in Fencing: Division of Clock Time
Learn about the mathematics of fencing, including the ratio of touches to time remaining that an athlete needs to mentally calculate in order to stay in the match, in this video from Center for Asian American Media. In the accompanying...
PBS
Pbs Learning Media: Real Life Math: Nurse
In this video, learn how mathematics--specifically, proportion, ratio, rate, and conversions--are used in the professional responsibilities of a registered nurse working on the surgical trauma floor. In the accompanying classroom...