Simple and compound machines are designed to make work easier. When we encounter a machine that does not fit this understanding, the so-called machine seems absurd. In this lesson, the cartoons of Rube Goldberg are introduced and engage the students in critical thinking about the way his inventions make a simple task even harder to complete. As the final lesson in the simple machines unit, the study of Rube Goldberg machines can help students evaluate the importance and usefulness of the many machines around them.

Students conduct an experiment to determine the relationship between the speed of a wooden toy car at the bottom of an incline and the height at which it is released. They observe how the photogate-based speedometer instrument "clocks" the average speed of an object (the train). They gather data and create graphs plotting the measured speed against start height. After the experiment, as an optional extension activity, students design brakes to moderate the speed of the cart at the bottom of the hill to within a specified speed range.

This task provides students with an opportunity to engage in Standard for Mathematical Practice 6, attending to precision. It intentionally omits some relevant information -- namely, that a typical soda can holds 12 oz of fluid, that a pound is equivalent to 16 dry ounces, and that an ounce of water weighs approximately 1.04 dry ounces (at the temperature of the human body) -- in the interest of having students discover that these are relevant quantities. The incompleteness of the problem statement makes the task more amenable to having students do work in groups.

This task uses geometry to find the perimeter of the track. Students may be surprised when their calculation does not give 400 meters but rather a smaller number.

The goal of this task is to model a familiar object, an Olympic track, using geometric shapes. Calculations of perimeters of these shapes explain the staggered start of runners in a 400 meter race.

The purpose of this task is for students to compare two fractions that arise in a context. Because the fractions are equal, students need to be able to explain how they know that.

In this task students use ratio and rate reasoning to solve the real-world problem of a runners rate and distance.

This activity compares a runaway slave ad and an abolitionist poster to explore the causes and effects of the 1850 Fugitive Slave Law. The law changed how many northerners viewed slavery and intensified conflicts that brought the nation closer to Civil War.

This task involves fraction multiplication and can be solved with pictures or number lines.

This task builds on a fifth grade fraction multiplication task, Ň5.NF Running to School, Variation 1.Ó This task uses the identical context, but asks the corresponding ŇNumber of Groups UnknownÓ division problem. See Ň6.NS Running to School, Variation 3Ó for the ŇGroup Size UnknownÓ version.

The purpose of this task is to help students extend their understanding of division of whole numbers to division of fractions, and given the simple numbers used, it is most appropriate for students just learning about fraction division because it lends itself easily to a pictorial solution.

This is a task from the Illustrative Mathematics website that is one part of a complete illustration of the standard to which it is aligned. Each task has at least one solution and some commentary that addresses important asects of the task and its potential use. Here are the first few lines of the commentary for this task: Alex, Mel, and Chelsea play a game that has 6 rounds. In each round there is a single winner, and the outcomes of the rounds are independent. For each ...

This is a task from the Illustrative Mathematics website that is one part of a complete illustration of the standard to which it is aligned. Each task has at least one solution and some commentary that addresses important asects of the task and its potential use. Here are the first few lines of the commentary for this task: Cecil has two six-sided dice, a red one and a white one. If Cecil throws the two dice, what is the probability that the red die is a 1? What is the pro...

This is a task from the Illustrative Mathematics website that is one part of a complete illustration of the standard to which it is aligned. Each task has at least one solution and some commentary that addresses important aspects of the task and its potential use.

This is a task from the Illustrative Mathematics website that is one part of a complete illustration of the standard to which it is aligned. Each task has at least one solution and some commentary that addresses important aspects of the task and its potential use.

This is a task from the Illustrative Mathematics website that is one part of a complete illustration of the standard to which it is aligned. Each task has at least one solution and some commentary that addresses important asects of the task and its potential use. Here are the first few lines of the commentary for this task: Sometimes hotels, malls, banks, and other businesses will present a display of a large, clear container holding a large number of items and ask custome...