Want an easy to use spreadsheet that does all the calculations for you?
All you have to do is type in what your OOP was, then type in what your savings was and the rest is calculated!
This is a google doc that you can find here.
As a quick reference - sign in to google doc's (or create an account if you need to) then go to file > download > and choose Excel. Once that pops up then hit file > save as > and choose a file location and name for your spreadsheet.
For those not used to working inside spreadsheets - in the column that says "spent" and the column that says "saved" you can type an = sign FIRST then the $ amount you spent or saved at a particular store. When you want to add another store to the week just click on the cell - in the address bar up top you'll see it says =2.00 (if you had typed 2.00 in the cell) ..... put a + after the 2.00 (no spaces required) and type the next value (you have to do this in the address bar) and hit enter. It will do the addition for you this way too!
It's a quick way to keep track of what you're spending and saving week over week....so you can watch that savings % grow and become excited. It also does year to date calculations for you and puts them right at the top of the spreadsheet!