Slide rule

NPR article: The Slide Rule: A computing device that put a man on the moon

 I remember my dad, who is and always has been an engineer who thinks in engineer and speaks engineer, marveling that my eighth grade geometry class included trig tables.  We quickly moved to scientific calculators and then the exciting world of graphing calculators.  I remember one of my friends making 6-slide flip books on the graphing calculator in the middle of non-math class, and even "taking notes" on it.  (We knew, and the teacher knew, he was drawing.  But he actually had English notes in there too, so she couldn't call him on it that time.) 

One time I forgot my graphing calculator and borrowed dad's scientific calculator... it threw me for a loop because not only did it have a cord and an adapter, you had to enter your data using reverse polish notation (Instead of 3 + 4 - 5, you type in 3  4  +  5  - ).  When he bought it, for several hundred dollars, it was really top end high tech.  After all, the whole of NASA when we sent men to the moon had less computing power than a flip phone has nowadays.