A matrix is an array of numbers.

The horizontal lines of the matrix are called rows and the vertical lines are called columns. The numbers in the matrix are called elements.

The size of a matrix is determined by how many rows and columns are in the matrix. A matrix with m rows and n columns is called an m x n matrix, where m and n are the dimensions of the matrix.
Take a look at the matrix below. Since there are 2 rows and 2 columns, we can call this a 2 x 2 matrix.

A matrix can be added or subtracted from a matrix of the same size. Take matrix A and matrix B below. Since matrix A and B are 2 x 2 matrices, we can add and subtract these matrices.

Let’s first try to add the matrices.

We first add the numbers from the first row and first column:

Then, we add the numbers from the first row and second column:

Next, we add the numbers from the second row and first column:

We finally add the numbers from the second row and second column:

Now, let’s try to subtract the matrices from each other.

Follow the same steps as above with addition. Did you get the same answer as shown below?