Curated OER
Which is Closer to 1?
A seemingly simple question that reveals a lot about a student's understanding of fractions. In finding an answer, learners compare fractions with different denominators that are both greater and less than one. No number line is...
Illustrative Mathematics
Designs
A resource that makes for excellent group work as students explore the area and perimeter of different complex designs made up of squares and circles. The commentary gives a clear definition of perimeter, but suggests that group members...
Illustrative Mathematics
Lines of Symmetry for Quadrilaterals
Explore how lines of symmetry help define different categories of quadrilaterals. Looking at a square, rectangle, trapezoid, and parallelogram, young mathematicians discover that each shape has its own, unique symmetry. Encourage your...
Illustrative Mathematics
Sum of Angles in a Polygon
How can learners use algebra to solve a geometry problem? Help learners create an equation that shows the relationship between the number of sides of a polygon and the sum of the interior angles. Students are asked to divide the...
Illustrative Mathematics
The Physics Professor
Help mathematicians see that a formula found in a physics book has an algebraic structure. Though the formula given in the resource looks complicated, learners are to break down the expressions and interpret each part separately....
University of Utah
Geometry: Transformations, Congruence, and Similarity
Rigid motions are to congruence as what are to similarity? Investigate properties of rigid motions and define congruence in terms of rigid motions with the ninth chapter of a 10-part eighth grade workbook series. The lesson then prompts...
West Contra Costa Unified School District
Dilations Using Right Triangles
Don't argue with a triangle that has a 90-degree angle. It's always right. Scholars first use right triangles to help draw dilations of points. They continue the instructional activity by applying this skill to draw dilations of polygons.
West Contra Costa Unified School District
Investigating Special Right Triangles
Scholars first investigate relationships in the side lengths of 30°-60°-90° triangles and 45°-45°-90° triangles. This knowledge then helps them solve problems later in the lesson about special right triangles.
West Contra Costa Unified School District
Solving Quadratic Equations – Alternative Methods
There's more than one way to solve quadratic equations. Scholars learn how to solve quadratic equations using alternate methods. They use completing the square by making the linear coefficient even and the leading coefficient a perfect...
West Contra Costa Unified School District
Evaluating Functions
Functions as inputs for other functions? After reviewing function notation and how to input values to evaluate functions, class members input functions into functions, essentially determining the composition of functions.
Statistics Education Web
Odd or Even? The Addition and Complement Principles of Probability
Odd or even—fifty-fifty chance? Pupils first conduct an experiment rolling a pair of dice to generate data in a probability instructional activity. It goes on to introduce mutually exclusive and non-mutually exclusive events, and how to...
Balanced Assessment
Above Average
Raise the bar and strive to be above average. The assessment task requires budding mathematicians to think critically and evaluate given statements. What does it truly mean to be above average?
Balanced Assessment
Triangle in Circle
Even kindergartners can draw triangles in circles, but the assessment task requires a bit more geometric knowledge. Scholars investigate triangles that have a diameter of a circle as one of its sides. They must consider triangles that...
Balanced Assessment
County Concerns
Apply area concepts to help farmers and settle county disputes. Scholars use a given diagram and information about an insecticide spraying campaign to determine the monetary benefit to farmers. They then decide which of two counties has...
West Contra Costa Unified School District
Solving Equations Using Balance Scale, Decomposition, and Graphing
There's more than one way to solve an equation — three, actually. Scholars learn how to solve simple linear equations in one variable using three different methods, which include using balance scales, using decomposition (e.g., turning...
West Contra Costa Unified School District
Three Forms of an Equation of a Line
An equation is an equation is an equation. Scholars see there are many ways to solve them when they first sort a set of linear equations as written in standard form, point-slope form, or slope-intercept. They then write equations in all...
West Contra Costa Unified School District
Parallel Lines Cut by a Transversal
Parallel lines seem so right for each other. It's too bad they'll never, ever meet. Learners use tracing paper to discover relationships among angles formed by two parallel lines cut by a transversal. They apply this information to find...
Statistics Education Web
Are Female Hurricanes Deadlier than Male Hurricanes?
The battle of the sexes? Scholars first examine data on hurricane-related deaths and create graphical displays. They then use the data and displays to consider whether hurricanes with female names result in more deaths than hurricanes...
Mathed Up!
Tree Diagrams
Explore how to visually represent probability problems. Scholars watch a video to refresh their memories on tree diagrams. To finish the activity, they complete a worksheet of questions on this topic.
Federal Reserve Bank
Lesson 2: In the Aftermath
Don't wait for a crisis to get your finances together. An economics lesson demonstrates the importance of understanding crucial documents, banking basics, and financial tools with the focus on Hurricane Katrina in 2005 and its effects.
Keep Your Children Safe
Hurt Tracker Math
Boost emotional intelligence and division skills with a three-question learning exercise featuring two imaginary towns that record when citizens hurt, forgive, or punish one another. Using division, scholars calculate each problem to...
Noyce Foundation
Through the Grapevine
Teach statistics by analyzing raisins. A thorough activity provides lesson resources for five levels to include all grades. Younger pupils work on counting and estimation, mid-level learners build on their understanding of the measures...
Noyce Foundation
Fractured Numbers
Don't use use a fraction of the resource — use it all! Scholars attempt a set of five problem-of-the-month challenges on fractions. Levels A and B focus on creating fractions and equivalent fractions, while Levels C, D, and E touch on...
CK-12 Foundation
Angle Measurement: Adding Angles
Build angles from angles. Using the Angle Addition Postulate, learners find the measures of unknown angles. The interactive simulation shows a visual representation of the postulate and allows individuals to manipulate the angles and...