Illustrative Mathematics
Equal Area Triangles on the Same Base II
A deceptively simple question setup leads to a number of attack methods and a surprisingly sophisticated solution set in this open-ended problem. Young geometers of different strengths can go about defining the solutions graphically,...
Chapman University
Derivative of sin x
Direct and to the point (the slope at a point that is) describes this one-page proof of the derivative of the sin(x). The definition of a derivative using a limit is the first step in this sequential, algebraic, explanation of how the...
Curated OER
Proof that One Equals Zero and Zero Equals Two
In this algebra worksheet, 11th graders complete proofs that show why properties are true. There are 2 proofs given with 8 required steps.
Curated OER
Preparation and Transition to Two-Column Proofs
Students investigate proofs used to solve geometric problems. In this geometry lesson, students read about the history behind early geometry and learn how to write proofs correctly using two columns. The define terminology valuable to...
Curated OER
Proof that 7 x 13 = 28
In this algebra activity, 11th graders prove that an equation is true through multiplication, addition and multiplication by dividing factors. Students verify through 3 different processes that 7x13=28.
West Contra Costa Unified School District
The Parallelogram Law
Use your pupils' sense of curiosity to explore the Parallelogram Law. Here is an activity that outlines a complete lesson from beginning to end, allowing pupils to follow a conjecture through to the proof stage.
Radford University
Parallel Lines, Transversals, and Angles: What’s the Connection?
Streets, bridges, and intersections, oh my! Parallel lines and transversals are a present in the world around us. Learners begin by discovering the relationship of the angles formed by parallel lines and a transversal. They then apply...
Illustrative Mathematics
Joining Two Midpoints of Sides of a Triangle
Without ever using the actual term, this exercise has the learner develop the key properties of the midsegment of a triangle. This task leads the class to discover a proof of similar triangles using the properties of parallel lines cut...
Inside Mathematics
Magic Squares
Prompt scholars to complete a magic square using only variables. Then they can attempt to solve a numerical magic square using algebra.
Curated OER
Mathematics
Twelfth graders explore a variation of proof. In this geometry lesson, 12th graders apply their knowledge of proof to different scenario. They use 3 different tiers to advance through the lesson.
Curated OER
The Power of Algebra
First graders explore patterns. They look for patterns in number problems and use algebra as a means of solving general problems. Students devise a strategy to solve the number problem.
Curated OER
Verifying Angle Relationships
In this verifying angle relationships worksheet, 10th graders solve and prove various types of problems related to the verification process of various angle relationships. They complete each of the two proofs shown step-by-step, giving a...
Curated OER
The Pythagorean Theorem Lesson 2
Learners discuss and review examples of the Pythagorean Theorem using a GSP, Geometer's Sketchpad, activity.
Beacon Learning Center
Angles and Algebra
Students calculate angle measure for triangles and complementary/supplementary angles. After a lecture/demo, students utilize a worksheet imbedded in this plan to gain practice.
ISTE
Macaroni Math - Unit Overview
It's not just for lunch, mini mathematicians make use of macaroni to model addition and subtraction of numbers up to 10. They place macaroni pieces on their desk and take away to model subtraction, then write subtraction story problems....
Curated OER
Add a Little Art to Your Math
Origami presents a beautiful way to express and test geometric and algebraic concepts.
Curated OER
Inequalities and Triangles
Students prove and apply theorems of triangle inequality and hinge theorem. In this geometry lesson plan, students will discuss which triangle is bigger and why. They will use theorems, such as Exterior Angle Inequality or the...
Curated OER
Continuous Probability Distributions
In this continuous probability distribution worksheet, students identify discrete and continuous distributions. They calculate the linear combination of the independent normal random variable and determine probabilities using exponential...
EngageNY
Prove the Pythagorean Theorem Using Similarity
Amaze your classes with the ability to find side lengths of triangles immediately — they'll all want to know your trick! Learners use the Pythagorean Theorem and special right triangle relationships to find missing side lengths.
Virginia Department of Education
Inductive and Deductive Reasoning
Introduce pupils to the two types of reasoning, inductive and deductive. Classmates work in pairs or small groups to learn the difference between the two and apply these reasonings to develop valid conclusions.
Shodor Education Foundation
Cross Sections
Use this activity on cross-sections of three-dimensional shapes in your math class to work on algebra or geometry Common Core standards. The instructional activity includes a list of relevent terminology, and a step-by-step process to...
Inside Mathematics
Number Towers
Number towers use addition or multiplication to ensure each level is equal. While this is common in factoring, it is often not used with algebraic equations. Solving these six questions relies on problem solving skills and being able to...
Curated OER
How Sharp Is Your Memory?
Students play a memory game as they explore reasoning. In this algebra lesson, students identify concepts using pictures and words. They model real life scenarios using hands on manipulatives.
EngageNY
Addition and Subtraction Formulas 1
Show budding mathematicans how to find the sine of pi over 12. The third lesson in a series of 16 introduces the addition and subtraction formulas for trigonometric functions. Class members derive the formulas using the distance formula...