Students learn about and practice converting between fractions, decimals and percentages. Using a LEGO® MINDSTORMS® NXT robot and a touch sensor, each group inputs a fraction of its choosing. Team members convert this same fraction into a decimal, and then a percentage via hand calculations, and double check their work using the NXT robot. Then they observe the robot moving forward and record that distance. Students learn that the distance moved is a fraction of the full distance, based on the fraction that they input, so if they input ½, the robot moves half of the original distance. From this, students work backwards to compute the full distance. Groups then compete in a game in which they are challenged to move the robot as close as possible to a target distance by inputting a fraction into the NXT bot.

This interactive web tool and lesson helps students count large numbers of things by using the mathematical structures of area and proportionality. Students use a ratio table to keep track of their work as they count the number of tiles required to cover a floor, and the time required to put those tiles in place.

Students discover the mathematical constant phi, the golden ratio, through hands-on activities. They measure dimensions of "natural objects"—a star, a nautilus shell and human hand bones—and calculate ratios of the measured values, which are close to phi. Then students learn a basic definition of a mathematical sequence, specifically the Fibonacci sequence. By taking ratios of successive terms of the sequence, they find numbers close to phi. They solve a squares puzzle that creates an approximate Fibonacci spiral. Finally, the instructor demonstrates the rule of the Fibonacci sequence via a LEGO® MINDSTORMS® NXT robot equipped with a pen. The robot (already created as part of the companion activity, The Fibonacci Sequence & Robots) draws a Fibonacci spiral that is similar to the nautilus shape.

Student groups are provided with a generic car base on which to design a device/enclosure to protect an egg on or in the car as it rolls down a ramp at increasing slopes. During this in-depth physics/science/technology activity, student teams design, build and test their creations to meet the design challenge, and are expected to perform basic mathematical calculations using collected data, including a summative cost to benefit ratio.

A gear is a simple machine that is very useful to increase the speed or torque of a wheel. In this activity, students learn about the trade-off between speed and torque when designing gear ratios. The activity setup includes a LEGO(TM) MINDSTORMS(TM) NXT pulley system with two independent gear sets and motors that spin two pulleys. Each pulley has weights attached by string. In a teacher demonstration, the effect of adding increasing amounts of weight to the pulley systems with different gear ratios is observed as the system's ability to lift the weights is tested. Then student teams are challenged to design a gear set that will lift a given load as quickly as possible. They test and refine their designs to find the ideal gear ratio, one that provides enough torque to lift the weight while still achieving the fastest speed possible.

Students explore the concept of similar right triangles and how they apply to trigonometric ratios. Use this lesson as a refresher of what trig ratios are and how they work. In addition to trigonometry, students explore a clinometer app on an Android® or iOS® device and how it can be used to test the mathematics underpinning trigonometry. This prepares student for the associated activity, during which groups each put a clinometer through its paces to better understand trigonometry.

In this activity, learners use their hands as tools for indirect measurement. Learners explore how to use ratios to calculate the approximate height of something that can't be measured directly by first measuring something that can be directly measured. This activity can also be used to explain how scientists use indirect measurement to determine distances between things in the universe that are too far away, too large or too small to measure directly (i.e. diameter of the moon or number of bacteria in a volume of liquid).

The goal of this task is to use geometry study the structure of beehives. Beehives have a tremendous simplicity as they are constructed entirely of small, equally sized walls. In order to as useful as possible for the hive, the goal should be to create the largest possible volume using the least amount of materials. In other words, the ratio of the volume of each cell to its surface area needs to be maximized. This then reduces to maximizing the ratio of the surface area of the cell shape to its perimeter.

This lesson focuses learners on the concept of 1,000,000. It allows learners to see firsthand the sheer size of 1 million, while at the same time providing learners with an introduction to sampling and its use in mathematics. Learners use grains of rice and a balance to figure out the approximate volume and weight of 1,000,000 grains of rice. This lesson guide includes questions for learners, assessment options, extensions, and reflection questions.

This lab exercise exposes students to a potentially new alternative energy source hydrogen gas. Student teams are given a hydrogen generator and an oxygen generator. They balance the chemical equation for the combustion of hydrogen gas in the presence of oxygen. Then they analyze what the equation really means. Two hypotheses are given, based on what one might predict upon analyzing the chemical equation. Once students have thought about the process, they are walked through the experiment and shown how to collect the gas in different ratios. By trial and error, students determine the ideal combustion ratio. For both volume of explosion and kick generated by explosion, they qualitatively record results on a 0-4 scale. Then, students evaluate their collected results to see if the hypotheses were correct and how their results match the theoretical equation. Students learn that while hydrogen will most commonly be used for fuel cells (no combustion situation), it has been used in rocket engines (for which a tremendous combustion occurs).

Students learn about radar imaging and its various military and civilian applications that include recognition and detection of human-made targets, and the monitoring of space, deforestation and oil spills. They learn how the concepts of similarity and scaling are used in radar imaging to create three-dimensional models of various targets. Students apply the critical attributes of similar figures to create scale models of a radar imaging scenario using infrared range sensors (to emulate radar functions) and toy airplanes (to emulate targets). They use technology tools to measure angles and distances, and relate the concept of similar figures to real-world applications.

This is a 3 act lesson by Dan Meyer.  In this lesson students ask and answer, "How long does it take the sink to fill up?", after viewing a video of a leaky fauct.

Working as a team, students discover that the value of pi (3.1415926...) is a constant and applies to all different sized circles. The team builds a basic robot and programs it to travel in a circular motion. A marker attached to the robot chassis draws a circle on the ground as the robot travels the programmed circular path. Students measure the circle's circumference and diameter and calculate pi by dividing the circumference by the diameter. They discover the pi and circumference relationship; the circumference of a circle divided by the diameter is the value of pi.

As part of a design challenge, students learn how to use a rotation sensor (located inside the casing of a LEGO® MINDSTORMS ® NXT motor) to measure how far a robot moves with each rotation. Through experimentation and measurement with the sensor, student pairs determine the relationship between the number of rotations of the robot's wheels and the distance traveled by the robot. Then they use this ratio to program LEGO robots to move precise distances in a contest of accuracy. The robot that gets closest to the goal without touching the toy figures at the finish line is the winning programming design. Students learn how rotational sensors measure distance, how mathematics can be used for real-world purposes, and about potential sources of error due to gearing when using rotation sensor readings for distance calculations. They also become familiar with the engineering design process as they engage in its steps, from understanding the problem to multiple test/improve iterations to successful design.

Pixar in a Box - Virtual Cameras is an engaging activity to assist students as young as grade 5 to explore how light and lenses in cameras work.  The lesson also focuses on ratios.  The following are the standards covered in this lesson:
Math:  CCSS.MATH.CONTENT.6.RP.A.3
Science:  MS-PS4-2 Develop and use a model to describe that waves are reflected, absorbed, or transmitted through various materials.

This task focuses on using rate language and developing the context of unit rates.  It also focuses on having students look at multiple strategies for solving ratios and encourages a teacher facilitated discussion of these different strategies.

This lesson is part of a series of lessons that indigenize math education by including an art of the Native American tribes of Wisconsin-Menominee, Oneida, Ojibway, Ho Chunk and Stockbridge-Munsee. Beading has become ubiquitous in indigenous culture and is a modern art form. This context may be familiar to indigenous students as well as others. The unit starts with ratio identification and writing and moves to solving ratio reasoning problems, rate reasoning problems, and ends with graphing relationships. These are meant to supplement or replace current lessons.

This lesson is called Cedar's Beads and provides ways to write ratios and represent comparison relationships mathematically.

This lesson is part of a series of lessons that indigenize math education by including an art of the Native American tribes of Wisconsin-Menominee, Oneida, Ojibway, Ho Chunk and Stockbridge-Munsee. Beading has become ubiquitous in indigenous culture and is a modern art form. This context may be familiar to indigenous students as well as others. The unit starts with ratio identification and writing and moves to solving ratio reasoning problems, rate reasoning problems, and ends with graphing relationships. These are meant to supplement or replace current lessons.

This lesson is called Cedar's Pattern and provides a visual basis for understanding and using tape diagrams and tables to find ratio equivalencies.

This lesson is part of a series of lessons that indigenize math education by including an art of the Native American tribes of Wisconsin-Menominee, Oneida, Ojibway, Ho Chunk and Stockbridge-Munsee. Beading has become ubiquitous in indigenous culture and is a modern art form. This context may be familiar to indigenous students as well as others. The unit starts with ratio identification and writing and moves to solving ratio reasoning problems, rate reasoning problems, and ends with graphing relationships. These are meant to supplement or replace current lessons.

This lesson is called Cedar's Beading Supplies as a context for solving rate problems.

This lesson is part of a series of lessons that indigenize math education by including an art of the Native American tribes of Wisconsin-Menominee, Oneida, Ojibway, Ho Chunk and Stockbridge-Munsee. Beading has become ubiquitous in indigenous culture and is a modern art form. This context may be familiar to indigenous students as well as others. The unit starts with ratio identification and writing and moves to solving ratio reasoning problems, rate reasoning problems, and ends with graphing relationships. These are meant to supplement or replace current lessons.

This lesson is called Better Buy as a way to practice unit rates.