Maddie's Matrices Lesson

By: Maddie McGuire

What are Matrices??

A Matrix can be defined as a rectangular array of numbers. symbols or expressions which are arranged into rows and columns. Matrices are used to be interpreted in many different ways and can undergo the four basic operations of algebra; addition, subtraction, multiplication, and division.

Adding Matrices!

Subtracting Matrices!

Multiplying Matrices!

Multiplying matrices is a bit tougher than adding and subtracting matrices. Matrices can only be multiplied if the number of columns in Matrix A is equal to the number of rows in Matrix B. Below is an example on how to multiply matrices.


The determinant is a useful value that can be computed from the elements of a square matrix, (which means the number of rows is 2 which is equal to the number of columns, 2). There are two ways we can solve determinants. The first way is using a square matrix, to find a square matrix determinant, you take the product of the two diagonals and subtract them.
The second way to find the determinant is with a 3 by 3 matrix, called the third order determinant.

What We Learned?!

  • How to add matrices
  • How to subtract matrices
  • How to multiply matrices
  • How to find the determinant of a matrix

Upcoming Assessments:

Quiz 4 - December 8th

Test 2 - December 10th