To add two matrices with whole number entries, each element in the first matrix is added to the corresponding element in the second matrix. Here’s an example:

If we have: $A = \begin{pmatrix} 2 & 3 \\ 5 & 7 \end{pmatrix} \quad \text{and} \quad B = \begin{pmatrix} 4 & 1 \\ 6 & 8 \end{pmatrix}$

Then their sum, $C = A + B$, is calculated as: $C = \begin{pmatrix} 2+4 & 3+1 \\ 5+6 & 7+8 \end{pmatrix} = \begin{pmatrix} 6 & 4 \\ 11 & 15 \end{pmatrix}$

Would you like details on matrix addition or have any questions?

Here are some related questions to explore:

1. How do you subtract two matrices?
2. What are the conditions for matrix addition to be valid?
3. How do you multiply two matrices?
4. What is a scalar multiplication in matrices?
5. How does matrix addition apply in real-world problems?

Tip: Always ensure matrices are of the same dimensions before adding them.