Think John Nash from A Beautiful Mind fluently rattling off a mind-bending succession of numbers, or Will Hunting pounding it out on the hallway chalkboard, mop in hand. My father's mathematical mumblings in that peanut butter aisle remind me of Faulkner's stream of consciousness (1).
It went something like this: So JIF is 20 cents per ounce, no that would be $3.00 but it's about 30 cents less so two 15's, so not 20 but 18 cents per ounce and even a little less since it is $2.69. And for Peter Pan again about 20 cents per ounce but that would be $3.20 so take off ahhhh just one so it's gonna be just one cent less than 20 cents per ounce, or 19 cents per ounce ... well maybe a little less but not less than 18 cents per ounce. So, JIF is the better buy!
All of that would roll off his tongue in like 8 seconds. And I would catch just enough to get it. Repeat this at the shoe store and at the home improvement store, and you get the idea. He was teaching me math and he didn't even know it. Maybe he did.
He'd come back to his senses after being transfixed for those 8 seconds and then ask me, Which one do you want?
You see it didn't matter whether we got the best deal or not. What mattered was that he taught me to think about numbers and to use them to my advantage. I could still make a decision apart from the numbers, but it would be an informed decision. (Note we never bought Smuckers because their price per ounce was 40 cents and well beyond the JIF and Peter Pan options.)
Now I've heard someone say, "I'm not a math person." Some have called me a genius because I can rattle off mathematical stream of consciousness now like that myself. (I think "genius" is a reach, but thank you for the compliment; I know enough about math to know I don't know much about math.) (2)
Whatever skill I have may be partly just genetics. True. But those genetics manifested themselves in those mathematical mumblings that I absorbed and made my own.
What I'm saying is that you don't have to be Will Hunting to work out some simple calculations. You can talk it out and yes have your calculator in hand if you need it.
Here's your takeaway: Whether you are good at math or not, talk with your kids about the cost of peanut butter.
I can honestly say that simple conversations like that changed my life. Thank you, Dad.
What can you teach your kids in the peanut butter aisle?
(2) If you feel like a little stroll through the world of mathematics - to see just how vast it really is - just take a peak at one of these two math resources: 3Blue1Brown on YouTube, and Wolfram Mathematics.