[Member Intro] Hello!

[Tigerninja]

I've already posted one thread but I thought I might as well introduce myself.

Hello!
I'm Tigerninja (which thankfully isn't my real name) and I'm interested in basically everything. That's a pretty good personality to have since everyone can talk to you about their special interests. I'm mostly interested in mathematics, and of course cubing. Prime factorization is underrated. I also know Python and some French.

I mostly speed solve 3x3 where I average about 20 seconds with a DaYan TengYun v3 M. I use some pretty advanced techniques but I suck at LL. I know 2-look OLL and almost full PLL. This is the explanation for my PB single being 12.36, I got a pretty easy F2L and two easy LL algs. I solve with my main hand being the right hand, but I'm left handed. This has lead to me sometimes solving OH because I want my left hand to have a bigger role in my cubing. I sometimes solve 4x4 too, where I average about 1:40, but I'm not actively practicing. I'm also (not very actively) learning 3BLD. My goal is to speedsolve more events.

I'm especially interested in "cube theory", right now 2LLL methods, with apparently could be related to math (yay).

 

[Isaiah Scott]

Welcome!

 

[abunickabhi]

Hi tigerninja, welcome yo!

 

[Isabellikesmaths]

Nice to see another leftie who likes maths. I agree that prime factorisation is underrated - when I’m reading a book, I remember what page I’m on by prime factorising it, and my dad and I play a game where we prime factorise 6 digit numbers. I also know some python, although I only really use it for doing maths.

 

[Tigerninja]

Hello! It's nice for me too to see another "leftie" who likes maths. Being able to prime factorise that big numbers is really cool! I couldn't even factorise 72 without Google by my side. I'm mostly using Python for math too, the only program I have saved on my computer is for finding divisibility rules of numbers. Prime factorisation was useful here too, since a number is divisible by 24 if (and only if) it's divisible by both 8 and 3.

Thanks Isaiah and abunickabhi too for welcoming me!

 

[Isabellikesmaths]

Being able to prime factorise big numbers basically comes from practice - it used to take me several hours to do them but I’m much quicker now. Your python program sounds really cool - divisibility rules are really cool - especially some of the weird ones like the one for 7! Prime factorisation is super useful for finding things like that. When I’m prime factorising a big number I tend to just subtract multiples of the number I’m checking, rather than use the divisibility rules other than for small numbers like 3, 9 etc. I have a python program for finding Pythagorean triples, which is very inefficient - I wrote it when I was 11; and a slightly better one for doing various different calculations with fractions. I also sometimes use it for approximations for probability by doing loads of iterations, which can be useful for checking my answer, particularly if it doesn’t pass the gut check. My favourite python program that I’ve ever written wasn’t even doing maths - I wrote it in a computer science lesson when I was 12 when we were meant to be learning basic python and all it did was play an alarm sound and shut down the computer if you didn’t enter the right code within 10 seconds. And say “welcome back, great and almighty master” if you did. It was very childish but it caught my teacher out several times, which my friends naturally found hilarious.

Are you familiar with the Monty Hall problem (the one where there are goats behind two doors and a car behind one and you pick a door and then the game master opens a door which isn’t the one you picked and doesn’t have the car behind it and then you’re more likely to get the car if you switch door than if you keep the same door)? I was so convinced that that was wrong that I ran 10,000 iterations on a python program, only to get a definitive answer of 1/3 the car if you stay, 2/3 if you switch. The only way I’ve been able to understand that is imagining it with a deck of cards with one of the jokers removed and then you’re looking for the other joker. After you pick your card, the game master turns over all the cards except 2 - the one you have picked and the one with the joker (or the joker and one other if you happen to have picked the joker). In this case it seems much more obvious to me that it’s better to switch - the chance that you picked the joker the first time is so low that it is much more likely now for the joker to be under the other card. I guess the thing that messes with the probabilities is the fact that the game master knows where the card/joker is. Personally, I think it’s a silly problem - I would much rather have goats and would probably choose to switch to the door that the game master had opened.

 

[Tigerninja]

For my Python program, I'm using three methods for finding divisibility rules, prime factorisation, manually checking multiples of the number to look for their modulo 10 value (even when not writing Python code, I'm writing modulo as %), and the "remove last digit, multiply it by eg. -2 and add it to the rest. You're pretty lucky to have had education in Python. I just loaned a book from the library and read it every evening for a week.

I've always had trouble with subtracting in my head. When I'm subtracting on paper, and "borrowing", Instead of adding 10 to the upper number and subtracting, I'm taking 10 minus their difference. I discovered this in maybe second grade, since it took too much time to subtract from a number bigger than 10.

I'm familiar with the Monty Hall problem. Since my two biggest distinctions are having football socks and being a nerd, sometimes people ask me whether they're smart. I tell them about the Monty Hall problem. If they want to know more, or want a proof, I tell them they're smart. I'm usually telling people this proof:

The door that you can switch to always has the thing that isn't behind your door.
If you chose the door with the car, there are just goats left, so there's a goat behind the closed door.
If you chose a door with a goat, Monty opens another goat door and there's only a car door left.
Two thirds of the time you choose a goat from the beginning, so if you switch there is a two thirds chance you will get a car.

The reason that the problem is so silly is because it was in a game show with Monty as host. I would also prefer a goat.