Learning Math in the Real World

Several years ago, thinking I might like to start a small business selling original scrapbook paper designs, I attended a workshop put on by the U.S. Small Business Administration. I still remember the speaker telling us we had to be able to perform mental math to succeed in business. Mental math is the ability to calculate quickly and accurately in your head, without a calculator.

I’m an English teacher. When students ask me, and they often do, exactly how many percentage points their grade will rise or fall based on a 10-point quiz, I always respond, “Do I look like a math teacher?” Ignoring the preposterous notion that I could have each student’s cumulative points memorized at the precise moment that I am handing out a quiz, the assumption that I could mentally calculate the effect of a score of 2 versus a 9 always astonishes me. No matter how often they ask the question.

About the time I was sitting in the workshop learning how important mental math is to the retail world, my daughter was sitting in an elementary school classroom struggling with math. Luckily, in sixth grade, she had a teacher who plucked her from confusion and turned math into a strength. However, even then, she had difficulty transferring her math skills into real world settings.

Taking a page from the independent living skills program, I began taking my daughter into the real world and forcing her to use her mental math in relatively stressful situations. Clothes shopping became an opportunity to hunt down clearance racks with their percentages off the original price, and do some mental estimations. She and I set up tables at street festivals and sold greeting cards and magnets she made. Customers waited patiently while she filled out receipts in her book, adding their purchases. One woman leaned over and told me, “I know what you’re doing here, and I think it’s wonderful.”

As stressful as shopping sales and running vendor booths may be, the most difficult mental math occurred at the farmers’ markets so we hit them on a weekly basis back in those days. Not all vendors were patient as they had customers to assist, and I understood that. One vendor, however, worked with my daughter each week and we became his loyal customers. He told my daughter that he had trouble with math as well, but had to learn to calculate in his head because he had to sell produce at the family stand. He assured her that she would learn as he had. Under his guidance, she started planning the salad ingredients for dinner and the meal’s vegetables. He helped her estimate how far the produce would go to feed a family of three, and to determine what she could buy with the cash in her hand. (It’s important that children use real money and calculate how much change they will get back. It’s also critical that children make the decisions and actually handle the transaction rather than relying on the adult to do it for them.)

My daughter learned to estimate how much lettuce to put into her bag to feed her family that night, a mental exercise in volume. She learned to mentally add up the cost of salad ingredients to make sure she didn’t surpass the amount of cash she had in her hand because I didn’t have more to give and the vendor couldn’t give away his food for free. As an extra bonus, the vendor encouraged her to try different vegetables and taught her how to identify the freshest ones. One night she even got her father to eat the dreaded Brussels sprouts and enjoy them.

Today, thanks to that vendor and those early days at the farmers’ market, my daughter is a confident grocery shopper, and someone who is willing to try new foods as well.