@science_quotes@c.im @freemo For engineering, is pretty valuable to know that the speed of sound (in air, near STP) is between 100 and 1000 m/s. Among other things, you know that if you compute an expected velocity for something of hundreds of meters per second, you need to think about taking aerodynamics and human safety into account that you wouldn't at lower velocities.

If you don't remember if is closer to 300 or to 400 m/s, sure, you can look that up. But knowing the order of magnitude of *every* potentially relevant phenomenon is fundamental to knowing which ones you can disregard.