On Sun, Apr 28, 2019, 22:02 Joh-Tob Schäg <johtob...@gmail.com wrote: > Hello Nehal, > I've been doing some catching up on these videos. > Mr. Alabhya Singh took quiet some time to explain this mathematical problem > with the different approaches. I recall that in Germany when i was > confronted with the same problem (apply + (range 1 N)), i was taught the > Gauss approach > (/ (* N (- N 1)) 2) directly. > I was not consciously aware that > (= (apply + (range 11 20)) (+ (apply + (range 1 10)) (* 10 10))) > Nice trick. >
Wonderful! Sessions shared here are first introduction to children of Lisp. Currently these aren't the tricks they're doing. They're toying with Emacs Scratch Buffer and simple symbolic expressions, trying to solve basic math problems they see in day to day life. That makes me recall an childhood incident where i came distressed from > Kindergarden (I would have been between 5 and 7) when i realized i ran out > of numbers to count. > > > My goal was to find the highest number i can count (looking back it's > that > > i run out of ways to say a number when i try to find the highest number i > > can say): > > > > "one,two,tree,(annoyed pause) this goes till ten like that" > > "eleven,twelve,(let's skip the small steps) next is twenty, then > > thirty,forty,fifty, this goes to slow as well, i never finish that way, > so > > next is one hundred, so next is one thousand, ten thousand, one hundred > > thousand, thousand thousand, (??) that sounds funny, so it must go on > like > > "thousand-thousand-thousand-..." and i now can say all the numbers" > > It turned out it did not. > > I found the next care taker and said "When i grow up i want make > > thousand-thousand €" > > He answered: "You mean like 2000€?" > > I was shocked, 2000 was way smaller than i had in mind. "No like > thousand, > > ten-thousand, hundred thousand, thousand-thousand, ten-thousand-thousand" > > He answered: "It is not thousand-thousand it is called a million" > > It dawned on me that for some stupid reason people decided to call > > thousand-thousand a million. Why would they want to do that it is way > more > > fun to say thousand-thousand-thousand than thousand-million? > > By the time i was ready to ask the question the staff had left in a hurry 😎
