The rule is add before multiplying, even with matrices. Pupils use a slider to change the scalar multiplying the sum of two matrices. The interactive displays the resulting solution matrix, and requires scholars answer five questions...

Discover the procedure to add and subtract matrices. Pupils use the interactive and discover the pattern in adding and subtracting matrices. Scholars adjust the entries in the addends and see the resulting changes in the sum. They also...

Squares can be magic. Pupils use their knowledge of addition of positive and negative rational numbers to create a 3 X 3 magic square where the sums are 1. Scholars create addition and multiplication expressions with a set of rational...

First graders are asked to find the missing numbers in subtraction and addition equations. Each missing number is represented with a box and appears as an addend, subtrahend, sum, or difference.

Stack the like terms to add vertically. The resource contains a visual aid to help with the addition of polynomials using the vertical method. Pupils use the aid to calculate the sum of two polynomials.

Count on tiles to add polynomials. Pupils drag virtual algebra tiles onto colored mats to represent the sum of two polynomials. The learners count the number of like tiles to find the coefficient of each term. They finish...

Build a pyramid of sums. An interactive presents the first five rows of Pascal's Triangle as a pyramid. Pupils match missing entries in the pyramid and continue the pattern to determine entries of other rows. The learners use the entries...

The sum of the parts is greater than the whole. An interactive uses a Venn-like model to show the percentage of females from a survey that have a blue dress, a red dress, or both. The pupils determine the numbers in each category...

Do words change or add meaning or interest to a work of art? The final lesson in a four-part series on the beautiful brain as a work of art focuses on art analysis. Scholars write a story about exploring art from the inside. Reflections...

Transform proofs using triangle rotations. By rotating a triangle around various points, class members develop proofs. Participants prove relationships of alternative interior angles formed by parallel lines and the sum of the interior...

Convert a table to probabilities. Pupils set up the winning rules for the sums of two dice. Using the rules, the applet fills out a table showing the winners for each combination. Learners determine the probabilities of winning for each...

Engage further in Esperanza Rising with a focus on close reading and metaphor. Class members zero in on the tenth chapter, examining characters and big ideas. Pupils discuss the text in small groups and as a whole class, and...

Math class is full of drama—there are so many problems to work out! Pupils work out factoring problems. They use quadratic methods of factoring higher degree polynomials, in addition to factoring the sum and difference of two...

Use the Law of Cosines and the Law of Sines to solve problems using the sums of vectors. Pupils work on several different types of real-world problems that can be modeled using triangles with three known measurements. In the process,...

The ninth part in a 25-part series emphasizes the importance of using properties of operations in evaluating sums and differences of rational numbers. Pupils solve problems and provide justifications for each step.

Pairs with the same sum of integer cards verify the addition and subtraction properties of equality by adding and subtracting like cards to each hand. They also justify the multiplication and division properties of equality using...

Find the cards that get to zero. The activity introduces the class to the idea of adding integers. Pupils use a number line to count up and count down when adding. They play a game to collect cards that will sum to zero.

Apply addition and subtraction of integers to solve problems with rational numbers. Pupils apply the rules for adding and subtracting integers to add and subtract rational numbers. Class members represent the problem with equations and...

Take a spin to determine experimental probability. Small groups spin a spinner and keep track of the sums of the spins and calculate the resulting probabilities. Pupils use simulated frequencies to practice finding other probabilities to...

Even or not, here I come. Groups investigate the parity of products and sums of whole numbers in the 17th activity in a series of 21. Using dots to represent numbers, they develop a pattern for the products of two even numbers; two odd...

Who knew the sum of a number's digits gives such interesting information? The 18th installment of a 21-part module has scholars investigate division by three and nine. After looking at several examples, they develop divisibility tests...

With endless possibilities, you can create custom flashcards to take to class as easy as 1, 2, 3! Let this flashcard creator do the work for you, just chose the level of difficulty, add or subtract, and the number of place values. Each...

Addition and subtraction are essential skills for all young mathematicians. Explain the step-by-step process with respect to place value using these real-world examples. Focus is on numbers in the tens, hundreds, and thousands, making...

Students find the proper factors for numbers one through fifty using either the divisibility laws or TI-82. They determine the sum of the proper factors for each number. If the sum of the factors is less than the number itself, then this...