Virginia Department of Education 
Integers: Addition and Subtraction
Young mathematicians construct their own understanding of integers with an inquiry-based math activity. Using colored chips to represent positive and negative numbers, children model a series of addition and subtraction problems as...
DataWorks
4th Grade Math: Multi-Step Word Problems
Solving word problems requires reading comprehension and math computation. Through an interactive slideshow presentation, fourth graders observe and follow each step toward solve multiplication and division word problems. 
State of Michigan
Pre-K Mathematics
Kick-start children's education with this pre-school math unit. Offering 31 different hands-on learning activities that develop young mathematicians' pattern and shape recognition, basic number sense, and much more, this is a...
University of Missouri
Money Math
Young mathematicians put their skills to the test in the real world during this four-lesson consumer math unit. Whether they are learning how compound interest can make them millionaires, calculating the cost of remodeling...
Curated OER
Adding & Subtracting (Combining) Integers
Maintain a positive atmosphere in your math class with this fun lesson on adding and subtracting integers. After first explaining the rules for combining positive and negative numbers, this resource uses a comic strip...
EngageNY
One-Step Equations—Addition and Subtraction
Just one step is all you need to find success in solving equations. The 27th installment in a series of 36 teaches how to solve one-step equations involving addition and subtraction. Tape diagrams help future mathematicians in this task.
CK-12 Foundation
Distance Between Two Points: Segment Addition
Examine the segment addition postulate through an online simulation activity. An interactive lesson allows scholars to manipulate points and watch as the lengths of segments change. Through their study, they are able to apply the Segment...
Math Learning Center
Grade 1 Supplement Set A4 – Number and Operations: Equivalent Names
Engage young mathematicians in developing their basic arithmetic skills with these great hands-on activities. Using Unifix® cubes to model a variety of single digit addition and subtract problems, children build a basic...
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...
School Mathematics Project 
Resource Sheets
This extensive and far-reaching collection of worksheets puts a new twist on many basic concepts. Learners use multiplication to trace a path from one point to another, tile a plane by converting between improper and proper fractions,...
CK-12 Foundation
Addition and Subtraction of Rational Expressions: Strawberry Sherbet Punch
Explore the connection between fractions and rational expressions. Young scholars manipulate fractions with unlike denominators to find a total. Challenge questions allow them to check their work to ensure they are correct.
EngageNY
Adding and Subtracting Rational Expressions
There's a fine line between a numerator and a denominator! Learners find common denominators in order to add and subtract rational expressions. Examples include addition, subtraction, and complex fractions.
EngageNY
A Surprising Boost from Geometry
Working with imaginary numbers — this is where it gets complex! After exploring the graph of complex numbers, learners simplify them using addition, subtraction, and multiplication. 
EngageNY
Read Expressions in Which Letters Stand for Numbers
Pencil in the resource on writing verbal phrases into your lesson plans. The 15th installment of a 36-part module has scholars write verbal phases for algebraic expressions. They complete a set of problems to solidify this skill.
EngageNY
Triangle Congruency Proofs (part 1)
Can they put it all together? Ninth graders apply what they know about proofs and triangle congruence to complete these proofs. These proofs go beyond the basic triangle congruence proofs and use various properties, theorems, and...
Visa
The Influence of Advertising
Pupils become informed consumers and citizens with this lesson on the influence of advertising, identifying basic advertising techniques and discriminating between fact and claim in modern advertisements and commercials.
CK-12 Foundation
Angle Measurement: Fuel Gauge Angles
Once you start looking, angles appear everywhere in our daily lives. A creative lesson has learners use the angles created by a fuel gauge to practice the Angle Addition Postulate. They see how changing the angle parts does not...
Whitman College
Calculus - Early Transcendentals
This textbook takes the learner from the basic definition of slope through derivatives, integrals, and vector multivariable calculus. Each section is composed primarily of examples, with theoretical introductions and explanations in...
Curated OER
Fractions: A Conceptual Approach
If you are teaching fractions to elementary learners this year, this Singapore Math presentation is essential to your curriculum. It addresses several basic fractions concepts in conceptual terms and figures, making each idea accessible...
Illustrative Mathematics
3-D Shape Sort
From the apple on your desk and the coffee cup in your hand, to the cabinets along the classroom wall, basic three-dimensional shapes are found everywhere in the world around us. Introduce young mathematicians to the these common figures...
Illustrative Mathematics
Equality Number Sentences
Understanding the concept of equality is fundamental to the success of young mathematicians. To explore this basic idea, children compare the dots arranged in pairs of rectangles in order to determine whether or not they contain an equal...
National Security Agency
Introducing Integers and Their Operations
There's nothing negative about this mini-unit on integers! Engaging young mathematicians in a series of hands-on activities and collaborative learning opportunities, this resource offers an excellent way to introduce your class...
Charleston School District
Solving with Inverse Operations
What does order of operations have to do with solving equations? A video explains solving two-step equations using a do/undo chart. Learners recognize the operations within an equation and use inverse operations to undo those...
Charleston School District
Solving Equations by Combining Like Terms
How do you make these x's get along? Building on the previous lesson in the series, learners solve equations by combining like terms. The video uses objects to help pupils understand the concept.