Enter the first matrix on the left and the second matrix on the right.
Now click on the .
Your answer appears at the bottom middle of the window.
You can only add matrices if they are the same size, that is, both have the same number of rows and both have the same number of columns. You can add a 3 by 4 to a 3 by 4, but you cannot add a 2 by 3 to a 3 by 5.
If you want to add 3 matrices, enter the first two, add them and use to move the answer to the left side. Now enter the third matrix on the right side and click .