One guides a slide rule to roughly the right position based on intuition, then homes in on the answer.
Calculators make people dumber.
I'm torn between doing all my math on 40 lb laser paper with an assortment of Staedtler Pigment Liners, or on my iPad Pro using the architectural drawing program Concepts. Either way, I'm drawing. A digital interface is like a bird taking flight when one becomes algorithmically involved.