How fast is the world spinning in miles per hour? In this lesson students use unit rates to find the speed at which the Earth rotates around the Equator, Tropic of Cancer, and Arctic Circle. Think the Earth spins at the same speed everywhere? Think again!

Students will

Given the circumference of the Equator, find the speed of a point on the Equator

Use the relationship between distance and time to reason about relative speeds

Given the circumferences of the Tropic of Cancer and the Arctic Circle, calculate the speeds there

Explain why the farther you travel away from the Equator, the more slowly you travel due to Earth's rotation

Before you begin

This is an application of d = rt with long distances. Students should have already been introduced to the idea of unit rate as it relates to speed: a speed tells you a distance traveled within one unit of time.

How hard is it to steal second base in baseball? Students use the Pythagorean Theorem and proportions to determine whether a runner will successfully beat the catcher's throw.

Topic:
Geometry (G), Ratios and Proportional Relationships (RP)

How do the rules of an election affect who wins? Students calculate (as a percent) how much of the electoral and popular vote different presidential candidates have received, and add with integers to explore elections under possible alternative voting systems.

Topic:
Number System (NS), Ratios and Proportional Relationships (RP), Reasoning with Equations and Inequalities (REI)

Why do certain pairs of notes sound better than others? Students use ratios and fraction division to explore what makes two notes sound good or bad when played together.

Topic:
Number System (NS), Ratios and Proportional Relationships (RP)

Is Wheel of Fortune rigged? Students use percents and probabilities to compare theoretical versus experimental probabilities, and explore whether the show is legit, or whether there might be something shady going on!

Topic:
Ratios and Proportional Relationships (RP), Statistics and Probability (SP)

How many calories does a body burn? Students interpret and apply the formula for resting metabolic rate (RMR) in order to learn about how calories consumed from food, calories burned from exercise, and calories burned automatically contribute to a body's weight.

Topic:
Expressions and Equations (EE), Ratios and Proportional Relationships (RP)

How much of your life do you spend doing different activities? Students use proportional reasoning and unit rates to calculate how much of their total lifespan they can expect to spend sleeping, eating, and working...and discuss how they'd like to spend the time that's left over.

When you buy a concert ticket, where does your money go? Students use percents and proportional reasoning to describe how revenue from tickets is distributed among the various players in the concert game.

How do you determine the best scorer in basketball? Students compare LeBron James and Tyson Chandler in various ways, from total points, to points per game/minute, to a new measure called net points in order to decide.

Topic:
Number System (NS), Ratios and Proportional Relationships (RP)

How do filmmakers create slow-motion and time-lapse videos? Students combine a camera's frame rate, a video player's frame rate, and proportional reasoning to explore movie magic.

Are Papa John's specialty pizzas a good deal? Students evaluate expressions to compare the prices of specialty vs. build-your-own pizzas, and determine how much they're saving...or losing!

Topic:
Expressions and Equations (EE), Ratios and Proportional Relationships (RP)

What size ice cubes should you put in your drink? Students use surface area, volume, and rates to explore the relationship between the size of ice cubes and how good they are at doing their job: chilling.

Topic:
Geometry (G), Ratios and Proportional Relationships (RP)

How much should people pay for cable? Students interpret scatterplots and calculate the costs and revenues for consumers and providers under both the bundled and à la carte pricing schemes to determine which would be better for U.S. companies and customers.

Topic:
Number System (NS), Ratios and Proportional Relationships (RP)

How much do different professionals earn in a year? Students use rates and ratio reasoning to compare how much a teacher, the President, and LeBron James earn...and to compare how much value the create.

How does the what we see affect our happiness? Students explore the concept of the jen ratio – the ratio of positive to negative observations in our daily lives – and use it to discuss how the content we consume and the things we observe influence our experience of the world.

How big is the White House? Students build scale models of the White House, compare scaling in one vs. two vs. three dimensions and design their ideal version of the president’s house.

Topic:
Geometry (G)

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Mathalicious lessons provide teachers with an opportunity to teach standards-based math through real-world topics that students care about.

How do the rules of an election affect who wins? Students calculate (as a percent) how much of the electoral and popular vote different presidential candidates have received, and add with integers to explore elections under possible alternative voting systems.

Topic:
Number System (NS), Ratios and Proportional Relationships (RP), Reasoning with Equations and Inequalities (REI)