I was shopping at Target and noticed a baby scale for sale for people who are unwilling or unable to do subtraction (see image below). The scale works by first weighing a person holding the baby, then weighs the person without the baby, and performs subtraction to yield the weight of the baby. Most digital scales these days are accurate enough to give a good estimate of a baby’s weight using the 2-weigh method for people who can do subtraction. The need for such a scale reflects poorly on the state of math in the US.
I posted this to twitter [here is the thread], where it was warmly greeted, so I decided to add it to the blog to give it a more permanent location.
On the upside ,the scale was on clearance for $11.98, down from $39.99. The shelf at Target was full of these scales. Perhaps new mothers are not too tired to do subtraction after all.