Eldon Clarey

“I mumbled something about how it was easy to calculate e to any power using that series (you just substitute the power for x). “Oh yeah?” they said, “Well, then, what’s e to the 3.3?” said some joker—I think it was Tukey. I say, “That’s easy. It’s 27.11.” Tukey knows it isn’t so easy to compute all that in your head. “Hey! How’d you do that?” Another guy says, “You know Feynman, he’s just faking it. It’s not really right.” They go to get a table, and while they’re doing that, I put on a few more figures: “27.1126,” I say. They find it in the table. “It’s right! But how’d you do it!” “I just summed the series.” “Nobody can sum the series that fast. You must just happen to know that one. How about e to the 3?” “Look,” I say. “It’s hard work! Only one a day!” “Hah! It’s a fake!” they say, happily. “All right,” I say, “It’s 20.085.”
― Richard Feynman, Surely You're Joking, Mr. Feynman! Adventures of a Curious Character