Do people not need estimate scale order of magnitude check and any number of other common tasks? I hold a number of mental models that I used to make all sorts

Do people not need estimate scale order of magnitude check and any number of other common tasks? I hold a number of mental models that I used to make all sorts of decisions. These don't need to be precise oh, but I often need them to be fast and or handy. Sometimes one needs the math just to think about things. Always needing a machine transfer the data in and out input and all of that is a real pain in the ass sometimes. Who wants that dependency?