This is an excellent short list of the main points I learned as an undergrad, and what I've retained today. One other point is that 64 bit floating points (aka

This is an excellent short list of the main points I learned as an undergrad, and what I've retained today. One other point is that 64 bit floating points (aka doubles) really are about double the precision of 32 bit floating points, in terms of significant digits. An interesting implementation detail is that they spend a higher fraction of their "bit budget" on the mantissa to get this (52 out of 64 bits, vs 23 out of 32).