Should math be taught in school ?

I told my kids when they were in school that math was the most important subject and to do their best to learn because if not use those skills to make money then they would need to know how to manage and account for it. My Dad was an farmer and excavator before he was killed at age 51. He could go out to a site with engineers to stake off a pond to be built and when they got through shooting elevations and distances after standing around talking a few minutes he would tell them how many yards of dirt would be in the dam. He would figure in his head without pencil and paper. After about 3 days the engineers would finally have to design and their figures would be very close to his. He had be taught shortcuts in school that wasn't even taught when I was in school and I graduated in 1967. Wish I had paid lots more attention to him because I have to use a pen and paper or calculator to figure yardage now, Joe