used yet add NUMBER_TOKEN thousand and subtract two I'll get the same as if I'd added up all of the numbers and in that case it's the same as putting a two at the start and then minus thing to from the number at the end so actually nice and and this is why it works with any number of columns as well because the exact same thing happens but you know I just don't have this here so I'd have one nine nine eight and the same thing would work and also there's there's an extra hidden thing built into these which i think is quite nifty which is that if you put the rods in this order I can tell you the total on the back is twenty eight thousand six hundred and thirty-two so if I flip those over you can see I've got my eight six three four which gives me twenty eight thousand six hundred and thirty-two but in fact this number here is the same as this number here and this number here is the same as this number here so they've deliberately because of course all you need is for those three to add up to eighteen you've got a bit of flexibility in there they've deliberately made it so that whatever this number is it's the same as that one so if I want to do the back I just look at this number read backwards so they're twenty two thousand seven hundred and twenty two I do always enjoy checking in to see what brilliant orgs problem of the week is there's a basic intermediate and advanced let's go for the basic one hey it says here Rakesh's spam filter predicts whether or not an email is spam it is accurate ninety-eight percent of the time and he knows that one percent of the emails sent to him are spam only one percent a dream of that which is more likely to be true if he receives an email that his filter predicts is spam the email is spam or the email is not spam while you think about that I'd like to thank brilliant for sponsoring this video brilliant dog is a website full of quizzes and puzzles and courses you can go through to get a better understanding of things like mathematics physics computer science they've got brilliant stuff and by doing all these quizzes and puzzles and sort of working your way through it you really get a better understanding of mathematics not just memorizing things or being told things you have to know but encouraging critical thinking really getting an understanding for things go and have a look at the website and if you go to brilliant org slash numberphile that links also in the video description you can get NUMBER_PERCENTAGE_TOKEN off brilliants Premium Membership and let's see if I'm ready for these intermediate and advanced all the intermediate ones got a snowman you
START_SPONSOR_TOKEN do always enjoy checking in to see what brilliant orgs problem of the week is there's a basic intermediate and advanced let's go for the basic one hey it says here Rakesh's spam filter predicts whether or not an email is spam it is accurate ninety-eight percent of the time and he knows that one percent of the emails sent to him are spam only one percent a dream of that which is more likely to be true if he receives an email that his filter predicts is spam the email is spam or the email is not spam while you think about that I'd like to thank brilliant for sponsoring this video brilliant dog is a website full of quizzes and puzzles and courses you can go through to get a better understanding of things like mathematics physics computer science they've got brilliant stuff and by doing all these quizzes and puzzles and sort of working your way through it you really get a better understanding of mathematics not just memorizing things or being told things you have to know but encouraging critical thinking really getting an understanding for things go and have a look at the website and if you go to brilliant org slash numberphile that links also in the video description you can get NUMBER_PERCENTAGE_TOKEN off brilliants Premium Membership and let's see if I'm ready for these intermediate and advanced all the intermediate ones got a snowman END_SPONSOR_TOKEN