# Grocery Store Math

I’ve been trying to keep my family’s food bill under control. For months. For years. I’ve tried various systems of math. One system was to bring a calculator to the store and add each item up as I put it into the cart. Once I would get to a determined amount, I’d stop shopping. (Well, kind of. If I needed black beans for my chili recipe or dish soap or any other essentials, I would still get them.) I liked this system because I never felt shocked when I got to the cash register to pay.

But once I had young children with–ahem, let me clarify–once I had young, mobile, wanting-things-for-themselves children, the system of using a calculator went out the automatic sliding doors. My three daughters would move about and make requests for corn niblets just because Dora’s face is on the can and my already random brain could not manage to keep track of them, answer no, and then return to the grocery list and inputting numbers into a small device.

Last week, I got brave and brought cash. I thought cash would be the ultimate in setting perimeters for myself. I wouldn’t want to embarrass myself by not having enough money, right? I went to the ATM and withdrew a large sum of twenty dollar bills. To mark my spending, every time I put \$20 worth of goods into the cart, I would move a twenty dollar bill from my wallet to a small pocket in my purse. I wanted to make sure I had the right amount of cash to cover the bill. Plus, again, I wanted an estimate of how much I was spending and try equate that to a pre-determined budgeted amount.

I thought I could, with the kiddos moving about and list of items to get, still manage counting to twenty. I thought that part would be easy. But those twenty dollar bills had to be moved from one place to another very fast. I would put orange juice, cheese, butter, cinnamon rolls into the cart. Move a twenty. Then, ham and sausage and Kaiser rolls.  Move a twenty. You get the idea. I would stop to the move the bills, re-direct my two little ones from touching this or that, and then get back to shopping in a bit of a fuzz. I couldn’t keep up with myself. The kids would want Pringles in the cart and then I’d take them out. And where was I again? (And a bummer: I was \$80 beyond my estimate at the cash register.)

At home, I looked at the last three grocery bills and realized that at the bottom of each receipt is a number of items purchased. I used that number to come up with an average, per item, to guesstimate my bill. I determined a per item average of around \$3.50. This morning when I went shopping my grocery math wasn’t quite perfect. I counted 60 items in my cart. My receipt said 67. (Keep in mind, I was still shopping with a toddler who wanted to push her own child sized cart about on her own path and at her own pace.) But for every item I put in the cart, I considered it a \$3 purchase no matter the real cost. And success! My estimated number was certainly closer than any other mental math I’ve tried before.