First create a freeform table with the numbers you want to visualize. To create a summary number, right click on the cell you want, then visualize, then summary number. If you click on the little green dot at the top right of the viz you can lock the selection, otherwise it will visualize whatever cell you click on.
For a summary change, you'll need to select 2 cells, right click, visualize, then summary change. It will display the % change between the two cells.