Curated OER
K-5 Mathematics Module: Number and Number Sense
Reinforce number sense with a collection of math lessons for kindergarteners through fifth graders. Young mathematicians take part in hands-on activities, learning games, and complete skills-based worksheets to enhance proficiency...
AAA Math
Aaa Math: Inverse Relationship of Addition & Subtraction
There is a great interactive problem set for students to practice the concept of the inverse property. This would be a great review before a unit on solving basic equations.
AAA Math
Aaa Math: Inverse Relationship of Subtraction and Addition
Students explore the inverse relationship of addition and subtraction. The resource provides self-check exercises and timed learning games to practice the concept.
AAA Math
Aaa Math: Complete a Numerical Sentence Subtraction
Students can practice solving subtraction equations through these interactive learning exercises. Three games are also available to challenge students' understanding of the skill.
AAA Math
Aaa Math: Inverse Relationship of Addition and Subtraction
This site introduces addition and subtraction fact families and provides an opportunity for students to practice the skill.
Beacon Learning Center
Beacon Learning Center: Checking Subtraction
Students can explore the inverse relationship of addition and subtraction in this interactive web lesson.
Varsity Tutors
Varsity Tutors: Hotmath: Algebra Review: Inverse Operations
Find a quick, concise explanation of inverse operations as in addition and subtraction, multiplication and division, and to a certain extent exponents and logarithms. Examples are given and clearly explained.
Washington State University
Washington State University: Real Numbers
This site from Washington State University provides properties and rules of addition and multiplication that help with proofs.
Texas Instruments
Texas Instruments: Matrices and Linear Equations
This Computer Algebra System (CAS) activity encourages students to investigate addition, subtraction, and multiplication of matrices. They find the inverse of a matrix. Students also solve a set of linear equations by using matrices.
Massachusetts Institute of Technology
Mit: Useful Trigonometric Identities
This list of trigonometric identities includes the factoring formulas near the bottom. A great tool for reference.
Math Cats
Math Cat: Fact Family Card
Everything you need to know about fact families can be found here. Discover what fact families are and learn different strategies for using them. Links included to print your own fact family cards, create a fact family house, and play a...
Other
Technical Tutoring: Trigonometry: The Very Fast Review
This site is a quick review of the functions and identities in trigonometry. Very helpful site.
NumberNut
Number Nut: Comparing Operations
Combine all of your knowledge about the four basic operations in this lesson that focuses on comparing operations. Discover the relationship between of each operation and key vocabulary terms to build your number sense.