I had the same math teacher all four years of high school--Mr. Dimmick. He taught math in a very logical and systematic way--just as it should be. He also made it seem like a game. We learned the rules of the game, and then we knew how to play. It seemed as easy as that. And he was very careful to make sure that we knew the rules.
Anyone, who has done much algebra, knows that there can be a lot of steps involved in solving a problem. Mr. Dimmick insisted that we be very systematic with our steps including making the unknown X that we were solving for with a tail. That way it would not be confused with X that was used for multiplication. Now to most, this seemed like an overkill. In fact, I've never run into anyone who had a math teacher who was this strict with the details and steps that needed to be shown in a problem.
However, this attention to detail paid off for me in college. When I was in my first calculus class, there came a point in the middle of the semester where complicated equations had to be broken down algebraically so they could be easily integrated. Most everyone in the class was confused when they were trying to do this. In fact, the teacher handed out worksheets so students could practice algebra again. But I didn't need them. Mr. Dimmick's careful teachings were still with me. Including making a tail on every unknown X in the equations.
I'll have to admit, decades later, I do not remember all of the math that Mr. Dimmick taught me, but I do remember that he taught me well and making my X's with a tail was an important part of that.
But wait there's more:
I remember a story Mr. Dimmick told one day about his four year old granddaughter. He asked her what zero meant. Her answer was, "That's when you don't hold up any fingers." He had a big grin as he told it and it made me smile too.