## All Lessons

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### Great Pacific Garbage Patch and Trash Wheels

6-8

In this lesson, students will explore the size of the Great Pacific Garbage Patch and learn how trash wheels help reduce the amount of plastic that pollutes our waterways. Students will then model a sampling method used to measure the amount of plastic collected by trash wheels.

### Disintegration of Plastic Items

6-8

In this lesson, students will learn what happens to plastic waste, how plastics disintegrate, and why plastics are so difficult to remove from waterways.### Crack the Code: Algebraic Generalizing with Manipulatives

6-8

Students us linking cubes and color rods to generalize patterns through differentiated game play.### Frustration: Analyzing a Card Game with Probability

6-8

This lesson engages students in the joy of mathematical inquiry through a game, while building number sense, understanding of uncertainty, statistical reasoning, and discourse skills. Students will explore the ideas of experimental and conditional probability through the card game, *Frustration*.

### Getting Positive About Integer Arithmetic

In this lesson, we share a series of tasks that can support students to order and compare signed numbers and develop multiple ways to reason productively about integer addition and subtraction.### Geometric Reflections

6-8

This lesson is based on the *MTLT*article, “Geometric Reflections: Why Should They Not Be Just a Flip?” by Dawn Teuscher, Shannon Dingman, Travis Olson, and Lisa Kasmer. In this lesson, students reflect points and figures to formulate a mathematical definition of reflection. Then, they identify and justify whether points and figures are reflections!

### Conditional Reasoning Online with Mastermind

6-8

This lesson is based on the *MTLT*article, “Conditional Reasoning Online with Mastermind” by Sean P. Yee, George J. Roy, and LuAnn Graul. This lesson engages students in using deductive and inductive reasoning as they play a game called Mastermind.

### Funky Protractors

3-5

This lesson is based on the *MTLT*article, “Funky Protractors for Exploring Angle Measures” by Hamilton L. Hardison. In this lesson, students recognize and justify the validity of a tool and differentiate angularity from nonangular features.

### Forecast Accuracy

People are apt to complain about weather forecasts and their accuracy. This is your chance to do something about them - or at least to understand their accuracy. In this lesson, students will gather data and crunch numbers to find out whether the weather forecasters are doing their jobs. Read the story behind Forecast Accuracy here.### Dollar Store Math

If you have taught math and you have shopped at the dollar store, how about combining the two? In this lesson students use toys from the dollar store to construct understanding of central data analysis and linear trends. Read the story behind Dollar Store Math here.### Analyze the Data

9-12

Students will analyze and graph the data taken.### Adjacent Circles

6-8

In this grades 6‑8 lesson, students are encouraged to discover all of the combinations for a given situation. They use problem-solving skills (including elimination and collection of organized data) to draw conclusions. The use of higher-level thinking skills (synthesis, analysis, and evaluations) is the overall goal.### Fact Families

Pre-K-2

In this lesson, the relationship of addition to subtraction is explored with books and with connecting cubes. Students search for related addition and subtraction facts for a given number using a virtual or actual calculator to find differences. They also investigate fact families when one addend is 0 as well as when the addends are the same.### Extending to Symbols

6-8

In Parts I and II of this investigation, students learn about the notion of equivalence in concrete and numerical settings. As students begin to use symbolic representations they use variables as place holders or unknowns. This part of the i-Math investigation illustrates the continued transition from the concrete balance view of equivalence to a more abstract view.### Exploring Diagonals and the Pythagorean Theorem

6-8

Students further explore square roots using the diagonals of rectangles. Using measurement, students will discover a method for finding the diagonal of any rectangle when the length and width are known, which leads to the Pythagorean Theorem.### Discovering the Area Formula for Triangles

6-8

In this lesson, students develop the area formula for a triangle. Students find the area of rectangles and squares, and compare them to the areas of triangles derived from the original shape.### Fair and Square: Using Concrete-Pictorial-Abstract Activities to Maximize Area

3-5, 6-8

Students discover the
relationships between area and perimeter as they prep for playing Square Off, a
wonderful Calculation Nation^{®}game. This lesson helps students understand the math of area and perimeter, which will help to maximize their scores when playing the game. Creating human-sized rectangles and working with geoboards provide concrete experiences before moving on to pictorial and abstract work with area and perimeter of rectangles.

### Deep Sea Duel

3-5, 6-8

Using the online game Deep Sea Duel, students play a card game against Okta. The objective is to choose cards so that some subset of three cards within their hand has a particular sum. Students will play several variations of the game, attempt to identify a winning strategy, and compare the game to other games that they know. ### Cutting Conics

9-12

Students explore and discover conic sections by cutting a cone with a plane. Circles, ellipses, parabolas, and hyperbolas are examined using the Conic Section Explorer tool. Physical manipulatives such as dough can optionally be used as well.