My dad (class of 55) knew enough to work in a job that would require an "engineer" today. By the time he retired he found he was teaching "engineers" the basics of trig and geometry THEY didnt know how to do. The man has penmanship you could die for....they dont teach that today either.
Then he didn't teach engineers, if you dont know trigonometry and calculus and how to apply it to practical problems then you are not an engineer. Nobody just 'knows' enough to be an engineer, I'm sure your dad was a smart cookie, but to be an engineer requires studying and an in-depth working knowledge of maths, physics, materials and statistics. Whilst I appreciate you have no respect for education and learning or the title of engineer, think of it this way, when I drive over a bridge I want to know that the bridge and car were designed by engineers not by someone claiming just claiming to 'know' that the bridge is strong enough or 'know' that the car's brakes can stop it. In much the same way that I go to a qualified doctor for medical advice I would go to a qualified engineer for advice on designing something to work correctly.
Assuming you are talking about manual engineering drawings when you refer to penmanship, that is not a skill an engineer needs, most engineers would not do their own detail drafting work. The ability to use a 3d modelling package is of more use to an engineer, it is more practical and less time consuming than manual drafting.
Why, if you have a calculator, would you want to do long division? Why not go the whole hog, give them trig tables or a slide rule.