Operations with Zero

By Allen Reed, Douglas Jensen

Learners review the basic math operations involving zero, emphasizing that division by zero is undefined. Examples are given.

Solving Equations: Properties of Equality

In this interactive object, learners examine the properties of equality and use those properties to solve simple equations.

International Time Zones (Screencast)

By Virginia Kirsch

In this screencast, you will learn about the 24 time zones.

The Rectangle

In this animated activity, learners read about the properties of a rectangle and its components. They then work practice problems to find the perimeter and area of rectangles.

Solving Trade Discount Problems (Screencast)

By David Nunenkamp

In this screencast, learners follow a step-by-step process to solve trade discount problems.

Fundamental Laws of Algebra

Learners review the fundamental laws of algebra including the commutative law of addition, the commutative law of multiplication, the associative law of addition, the associative law of multiplication, and the distributive law. Examples are given.

The Rectangular Solid

Learners study the properties of a rectangular solid and use geometric formulas to find volume and surface area.

Solving Systems of Linear Equations Using the Addition or Subtraction Method

In a series of practice problems, learners use the addition or subtraction method to solve systems of linear equations, also called "simultaneous linear equations."

The Right Circular Cylinder

Learners study the properties of a right circular cylinder and use geometric formulas to find volume and surface area.

The Parallelogram

In this animated activity, learners read the definition of a parallelogram and then find the perimeter and area of parallelograms in practice problems.

Numerical Curiosities: Part 4

By Jeganathan Sriskandarajah

In this fourth part in a series, learners follow the steps of the “mathemagician” to examine three numerical curiosities: Be a Psychic by Predicting Birthdays, Predict a Card with Mind Reading, and Predict the Three Die Values Your Opponent Has Rolled. Learners will also study palindromic numbers and look at two alphametric puzzles.

The Triangle

Learners examine the properties of a triangle and work practice problems to find a triangle's perimeter and area.

The Cube

Learners study the properties of a cube and use geometric formulas to find volume and surface area.

Simplifying Algebraic Expressions: Addition & Subtraction

Learners read definitions of the terminology associated with algebraic operations and then follow steps to simplify algebraic expressions.

Ratios and Proportions

In this interactive object, learners simplify ratios and solve problems using proportions. All terms are defined.

Standard-Position Angles and Reference Angles

By Kevin Ritzman

The learner will recognize standard-position angles and find the reference angle for any standard-position angle.

Simplifying Algebraic Expressions: Multiplication

Learners read definitions of the terminology associated with algebraic operations and then follow steps to use the fundamental laws of multiplication to simplify algebraic expressions.

Numerical Curiosities: Part 2

In part 2 of this series, learners follow the steps of the “mathemagician” to examine these numerical curiosities: The 189 Challenge; An Armstrong Number: What’s Special About 153? Is 495 Different or Indifferent? Is 6174 Different or Indifferent? It is always 618, and Beginning and Ending the Same.

The Trapezoid

In this interactive object, learners study the properties of a trapezoid and use a geometric formula to find its perimeter and area.

The Regular Square Pyramid

Learners study the properties of a regular square pyramid and use geometric formulas to find volume and surface area.

The Mathematics of Buying: Putting It All Together

By Mary Lee Rudnick-Kaun

Learners tackle this interactive learning object after studying the mathematics of buying. This activity ties together the ideas of net cost, list price, trade discounts, cash discounts, net cost equivalent, and single discount equivalent, as well as the concepts of part, base, and rate.

Solving Systems of Linear Equations Using the Substitution Method

In a series of practice problems, learners use the substitution method to solve systems of linear equations, also called "simultaneous linear equations."

The Square

In this animated activity, learners read about the properties of a square and its components. They then work practice problems to find the perimeter and area of squares.

The Right Circular Cone

Learners study the properties of a right circular cone and use geometric formulas to find volume and surface area.

Numerical Curiosities: Part 3

In this interactive object, part 3 in a series, learners follow the steps of the “mathemagician” to examine four numerical curiosities: What’s Special About 1089, Perfect Squares: 1089 and 9801, The Mathematical Significance of 1776, and The Calculator Number Game. The learner will also study six number patterns and look at one remarkable table. Immediate feedback is provided.