math, algebra whatever is is called now

I feel DUMB. cm/sec to mph and other conversions. I hate showing my work! I never did it in school. My way was not the teachers way but I would come up with right answer. Now teen must show work and do it very different than I learned (algebra was a long time ago)  Quadratic equation on paper is no problem, I do not know how to do it using a calculator. Damn, I am going to have to go back to school just to help teen with work!