Curated OER
The Circumference of a Circle and the Area of the Region it Encloses
Bring your math class around with this task. Learners simply identify parts of a given circle, compute its radius, and estimate the circumference and area. It is a strong scaffolding exercise in preparation for applying the formulas for...
Math Learning Center
Grade 2 Supplement Set D5 – Measurement: Telling Time
Have your class play concentration memory games using analog and digital clocks. Second graders become little experts with time telling to the minute, quarter, half, and hour. Use as a fun Friday treat as well as other...
Curated OER
Measuring the Area of a Circle
When mathematical errors happen, part of the learning is to figure out how it affects the rest of your calculations. The activity has your mathematicians solving for the area of a circular pipe and taking into consideration any errors...
EngageNY
Similar Triangles in Circle-Secant (or Circle-Secant-Tangent) Diagrams
First angle measures, now segment lengths. High schoolers first measure segments formed by secants that intersect interior to a circle, secants that intersect exterior to a circle, and a secant and a tangent that intersect exterior to a...
EngageNY
The Angle Measure of an Arc
How do you find the measure of an arc? Learners first review relationships between central and inscribed angles. They then investigate the relationship between these angles and their intercepted arcs to extend the Inscribed Angle Theorem...
EngageNY
From Circle-ometry to Trigonometry
Can you use triangles to create a circle? Learners develop the unit circle using right triangle trigonometry. They then use the unit circle to evaluate common sine and cosine values.
EngageNY
Secant Lines; Secant Lines That Meet Inside a Circle
Young mathematicians identify different cases of intersecting secant lines. They then investigate the case where secant lines meet inside a circle.
Willow Tree
Circle Graphs
Pie isn't just for eating! Scholars learn to create pie charts and circle graphs to represent data. Given raw data, learners determine the percent of the whole for each category and then figure out the degree of the circle that percent...
Illustrative Mathematics
Seven Circles III
A basic set-up leads to a surprisingly complex analysis in this variation on the question of surrounding a central circle with a ring of touching circles. Useful for putting trigonometric functions in a physical context, as well as...
Mathematics Vision Project
Circles: A Geometric Perspective
Circles are the foundation of many geometric concepts and extensions - a point that is thoroughly driven home in this extensive unit. Fundamental properties of circles are investigated (including sector area, angle measure, and...
Alabama Learning Exchange
Unit Circle: Special Angles—Just Know One
It's all about the patterns! Young scholars learn that the unit circle repeats itself in all four quadrants. Using these patterns, they evaluate the sine, cosine, and tangent of special angles.
Mathematics Vision Project
Module 5: Circles A Geometric Perspective
Circles, circles, everywhere! Pupils learn all about circles, central angles, inscribed angles, circle theorems, arc length, area of sectors, and radian measure using a set of 12 lessons. They then discover volume formulas through...
Virginia Department of Education
Going the Distance
Estimate the value of one of the most famous irrational numbers. The hands-on lesson instructs classmates to measure the circumference and diameters of circles using yarn. The ratio of these quantities defines pi.
Illustrative Mathematics
Coins in a Circular Pattern
What starts as a basic question of division and remainders quickly turns abstract in this question of related ratios and radii. The class works to surround a central coin with coins of the same and different values, then develops a...
Curated OER
Triangles Inscribed in a Circle
Are you tired of answers without understanding? Learners can give a correct response, but do they really understand the concept? Have young mathematicians think deeper about linear functions, angles, and formulas in algebra....
Federal Reserve Bank
FRED in the Classroom: Measures of Inflation
Don't just tell class members about how to measure inflation, have them experience it firsthand by asking them to work with real data and construct graphs!
Illustrative Mathematics
Paper Clip
With minimal setup and maximum freedom, young geometers are encouraged to think outside the box on a seemingly simple application problem. Though the task seems simple, measuring a given paper clip and finding how many 10 meters can...
101 Questions
Rotonda West, FL
The shortest distance from point A to point B is a straight line—or is it? Young scholars determine the shortest route either along a circular path or through the center of the circle. Learners gain a unique perspective on arc length and...
Curated OER
The Metric System
Applying this metric worksheet, mathematicians will provide standard metric units of measurement, identify the largest and best way to measure items using the metric system, and convert units using King Henry.
Illustrative Mathematics
Running Around a Track I
The accuracy required by the design and measurement of an Olympic running track will surprise track stars and couch potatoes alike. Given a short introduction, the class then scaffolds into a detailed analysis of the exact nature of the...
Noyce Foundation
What's Your Angle?
Math can be a work of art! Reach your artistic pupils as they explore angle measures. A creative set of five problems of varying levels has young learners study interior and exterior angle measures of polygons. The introductory levels...
Illustrative Mathematics
Two Wheels and a Belt
Geometry gets an engineering treatment in an exercise involving a belt wrapped around two wheels of different dimensions. Along with the wheels, this belt problem connects concepts of right triangles, tangent lines, arc length, and...
West Contra Costa Unified School District
What Is a Radian?
Here's an algebra II activity that strives to make the concept of a radian less abstract and more conceptual. It takes a hands-on approach to exploring the idea of a radian and allows individuals to develop a definition of a...
Alabama Learning Exchange
Radians: Just Another Way
Serve up angle measurements on paper plates. Pupils use paper plates and paper-folding techniques to create a unit circle with conversions for special angles. Using their plates, learners explore the relationship between angle...