Not quite separate...not quite together...

Adam and I stopped by the supermarket tonight to pick up some groceries. As Adam diligently browsed the Rice-a-Roni/Pasta-Roni aisle with his coupon in hand, I realized that these boxes of Pasta-Roni Adam was purchasing would become my Pasta-Roni in just two weeks and I wasn't sure whether I even liked Pasta-Roni. Twenty minutes later, as we were checking out, I noticed that Adam had placed a conveyor belt divider seperating our purchases. The following is a reconstructed conversation:

plasticann: Why don't we just pay together?
Adam: Well, if we keep our groceries separate, we won't have to divide them later so it'll be easier....plus, I like seeing how much I've saved...the percent at the bottom of the receipt.
plasticann: So, you're concerned my purchases will drag down your "percentage saved" number?
Adam: Well yeah...none of your items are on sale and I even used coupons.
plasticann: [pointing to the grapes, yogurt and mix] This, this and that are on sale.
Adam: [reluctantly] I guess.
***a few minutes later as Adam kindly swipes his credit card through and pays for plasticann's groceries
Adam: [admiringly] Wow...those grapes are a lot off!
plasticann: [examining her receipt] Yeah, only 79 cents a pound. Where's the percentage saved?
Adam: [pointing] Here...you saved 33%.
plasticann: Not bad, how much did you save?
Adam: 32%
plasticann: Booyah! Ha Ha!

Note: I didn't even have to clip coupons. Thanks to my steeply discounted grapes, I still beat Adam despite my full priced butter and Coffeemate.