My first job out of high school was selling wheels and tires. Out on the sales floor, we had a book with prices in it, and we had standard prices for labor and accessories such as valve stems and chrome lug nuts. My manager was utterly amazed that I could figure a total package deal for a set of wheels and tires, with all the accessories, including tax and labor, in my head, while talking to the customer, and be accurate within a buck or 2. I learned to do math in my head because I had horrible issues learning to write quickly in elementary school, and by high school, I had given up on a calculator, as I was always losing 'em. Kids today never learn to do the math without a calculator or computer....![]()