Historically, science has made great strides because someone cared to ask, how much? This is my concerted effort towards numerical literacy in the modern world. Assigning tangible quantities is immensely effective towards understanding the metaphorical "gravity of the situation".
All values are approximate and meant to facilitate back-of-the-envelope calculations. I highly recommend Measurement: A Very Short Introduction for a short history of measurements, and a crash-course in how different fields have evolved in assigning numbers to phenomenon.
See also Daniel Lemire's A short history of technology.