Scholastic
Study Jams! Classify Quadrilaterals
Face the vertex of two-dimensional shapes and discover what each figure requires as part of its classification. With one shape per slide, learners see what makes each shape special and compare it to others with similar qualities.
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Arcs and Chords
You've investigated relationships between chords, radii, and diameters—now it's time for arcs. Learners investigate relationships between arcs and chords. Learners then prove that congruent chords have congruent arcs, congruent arcs have...
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Arc Length and Areas of Sectors
How do you find arc lengths and areas of sectors of circles? Young mathematicians investigate the relationship between the radius, central angle, and length of intercepted arc. They then learn how to determine the area of sectors of...
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Inscribed Angle Theorem and Its Applications
Inscribed angles are central to the lesson. Young mathematicians build upon concepts learned in the previous lesson and formalize the Inscribed Angle Theorem relating inscribed and central angles. The lesson then guides learners to prove...
Computer Science Unplugged
Divide and Conquer—Santa’s Dirty Socks
The story "Santa's Dirty Socks" provides learners an example of a search algorithm that uses a divide and conquer system similar to a binary search algorithm. The included questions expand upon the concepts that follow the story.
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Unknown Length and Area Problems
What is an annulus? Pupils first learn about how to create an annulus, then consider how to find the area of such shapes. They then complete a problem set on arc length and areas of sectors.
Noyce Foundation
Granny’s Balloon Trip
Take flight with a fun activity focused on graphing data on a coordinate plane. As learners study the data for Granny's hot-air balloon trip, including the time of day and the distance of the balloon from the ground, they practice...
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How Do Dilations Map Angles?
The key to understanding is making connections. Scholars explore angle dilations using properties of parallel lines. At completion, pupils prove that angles of a dilation preserve their original measure.
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Dilations as Transformations of the Plane
Compare and contrast the four types of transformations through constructions! Individuals are expected to construct the each of the different transformations. Although meant for a review, these examples are excellent for initial...
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The Volume Formula of a Sphere
What is the relationship between a hemisphere, a cone, and a cylinder? Using Cavalieri's Principle, the class determines that the sum of the volume of a hemisphere and a cone with the same radius and height equals the volume of a...
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The Volume Formula of a Pyramid and Cone
Our teacher told us the formula had one-third, but why? Using manipulatives, classmates try to explain the volume formula for a pyramid. After constructing a cube with six congruent pyramids, pupils use scaling principles from...
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Definition and Properties of Volume
Lead a discussion on the similarities between the properties of area and the properties of volume. Using upper and lower approximations, pupils arrive at the formula for the volume of a general cylinder.
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Proving the Area of a Disk
Using a similar process from the first lesson plan in the series of finding area approximations, a measurement resource develops the proof of the area of a circle. The problem set contains a derivation of the proof of the...
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Properties of Area
What properties does area possess? Solidify the area properties that pupils learned in previous years. Groups investigate the five properties using four problems, which then provide the basis for a class discussion.
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Using Trigonometry to Determine Area
What do you do when you don't think you have enough information? You look for another way to do the problem! Pupils combine what they know about finding the area of a triangle and trigonometry to determine triangle area when they don't...
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Trigonometry and the Pythagorean Theorem
Ancient Egyptians sure knew their trigonometry! Pupils learn how the pyramid architects applied right triangle trigonometry. When comparing the Pythagorean theorem to the trigonometric ratios, they learn an important connection that...
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Sine and Cosine of Complementary Angles and Special Angles
Building trigonometric basics here will last a mathematical lifetime. Learners expand on the previous lesson in a 36-part series by examining relationships between the sine and cosine of complementary angles. They also review the...
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Adding and Subtracting Expressions with Radicals
I can multiply, so why can't I add these radicals? Mathematicians use the distributive property to explain addition of radical expressions. As they learn how to add radicals, they then apply that concept to find the perimeter of...
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Families of Parallel Lines and the Circumference of the Earth
How do you fit a tape measure around the Earth? No need if you know a little geometry! Pupils begin by extending their understanding of the Side Splitter Theorem to a transversal cut by parallel lines. Once they identify the...
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Between-Figure and Within-Figure Ratios
Tie the unit together and see concepts click in your young mathematicians' minds. Scholars apply the properties of similar triangles to find heights of objects. They concentrate on the proportions built with known measures and solve to...
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Dilations from Different Centers
Can you follow a composition of transformations, or better yet construct them? Young mathematicians analyze the composition of dilations, examining both the scale factor and centers of dilations. They discover relationships for both...
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How Do Dilations Map Lines, Rays, and Circles?
Applying a learned technique to a new type of problem is an important skill in mathematics. The lesson asks scholars to apply their understanding to analyze dilations of different figures. They make conjectures and conclusions to...
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Incredibly Useful Ratios
Start the exploration of trigonometry off right! Pupils build on their understanding of similarity in this lesson that introduces the three trigonometric ratios. They first learn to identify opposite and adjacent...
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Special Relationships Within Right Triangles—Dividing into Two Similar Sub-Triangles
Why are right triangles so special? Pupils begin their study of right triangles by examining similar right triangles. Verifying through proofs, scholars recognize the three similar right triangles formed by drawing the altitude. Once...