So we need cells C1, C2, C3 and C4 to be active. In Excel, you can do this by highlighting the cells.
Place your mouse over cell C1. Your pointer changes its shape to white cross. When your pointer changes to the white cross, hold your left mouse button down and drag to cell C4. Now leave the left mouse button when the cells are highlighted. The figure shown below:
Now to center the text and numbers, from the Microsoft Excel Ribbon locate the Alignment panel. You can see it from the figure shown below:
You can see the different alignment option, like this:
Hold your mouse over each alignment icon and you will see what happened to the highlighted cells when you move your mouse to each alignment icon. The text and numbers in cells C1, C2, C3 and C4 should now be centered, and your spreadsheet will look like this: