This may sound silly but teaching my daughters how to read a tape measure, I get calls I need a board, how long? 12" and 3 ticks. What is a tick?, is it a big tick, medium tick, or a really small tick?. Also simple math regarding fractions, one daughter who would like to do stuff in my shop, I told her she would have to pass a written test in math, she failed many times, her response was that she would just keep cutting until it fits. It amazes me how bad kids are at math now a days. Being a structural steel designer I can do metric, fractions, decimal fractions, and decimal feet in my head. An example; lets say a cashier rings you up and you show them a $20 bill, then say wait take the 20 back, and give them $14.36, almost every time they give you a blank stare and they are lost.