Math Encounters -- Secrets of Mental Math

Prepare to be mesmerized as award- winning Harvey Mudd Professor of Mathematics Arthur Benjamin demonstrates (and explains!) how to do rapid mental calculations and other amazing feats of mind. Arthur will be introduced by master magician Mark Mitton.
Math Encounters is a public presentation series celebrating the spectacular world of mathematics and presented by the Simons Foundation and the National Museum of Mathematics.
For further information, call the Museum of Mathematics at [phone] or e-mail [e-mail].

[@benjaminfranklin4149]

I love his version of the 4x4 magic square with a audience member's birthday. Makes it so entertaining and adds a personal touch.

[@zoreal99]

Not only he is a distinguished professor, but he's also a brilliant entertainer. He has a course called secrets of the mental math available on the great course website

[@premlatapremlata2205]

what is the website

[@tamarawiggall4457]

This chap is a sheer genius & a joy to watch - he's given me a very inspirational attitude to math 😃👍

[@BMiBudz]

this guy is phenomenal truely appreciate maths so much more thnx to people like him

[@adrianpeirson5027]

Fabulous, thanks for sharing.

[@moezhizi7265]

I really enjoy watching this

[@ericwazner6521]

Truly amazing! Thank you for sharing ❤👍

[@tonydauto822]

I wish I loved anything as much as he loves math. These are the kind of teachers/professors you remember your whole life.

[@MoonLiteNite]

Never seen a magic square use the top 4 row. i seen hundreds of examples but never seen them in the top like that, pretty cool!

[@rowedaescueta1400]

Love him

[@LEITWOLFfilm]

If you can't watch the full video, don't miss the song at 59:23 ;) It's great!

[@Abaddox]

This is why I love Math professors like him. I want him to be my professor!

[@Abaddox]

Not only because he is genius, but he is entertaining. He has the passion of math which he loves teaching so he is entertaining on teaching Math.

[@richards5800]

PLEASE ADD PDF OF HAND OUT TO VIDEO DESCRIPTION

[@crikeymos22]

What a load of old tosh. Old tosh that this has only received 528 likes. I am blown away by what I have learned here today. Wowskers. This should have a gazillion likes.

[@MattiK2609]

I wish he had been my math teacher in school...

[@pinolazerat65]

All schools should teach this better system, makes you wonder why they keep us stupid

[@davidivanelucas6992]

15:00 is

[@lucasrodriguez6351]

I loved the Pi song

[@pauldavis8146]

nerd

[@gotz2grind]

Captain Caveman in the background to the right.

[@Comoroo]

“Where are the women?” Shouts the whacko

[@mishaaskar3323]

Who is Scott Flanburg- the holder of the Guinness Book of World Records as the fastest Human Calculator?...

[@yla7153]

Question: How could he filled the rest of the numbers at 15:00 ??

[@kwilson5832]

He copies the number in the second column of the first row to the first column of the fourth row. Then, in the box in the second column of the third row, he adds 1 to the number in the third column of the first row. He then has three of the four numbers in the diagonal from bottom left to top right. He knows what the total should be, so can place the missing value in the third column of the second row. He knows that the four numbers in the top right quadrant also add up to the same total, so he can add the missing value to the fourth column of the second row. He knows that the four corners replicate the desired date, going anti-clockwise from the top left, so can add the missing value to the fourth column, fourth row. He now has three numbers in the fourth column, so can add the missing one to the third row. Moving on to the centre top quadrant, he already has three numbers, so can add the missing value to the second column, second row. He can then fill in the missing number in the first column, second row, by adding the second row or the top left quadrant. He can then fill in the number in the third column, third row, as he already has three numbers in the centre quadrant (and also the top left to bottom right diagonal). Then, he's only missing one number from each of three columns, so can add the missing numbers to make the columns add up to the desired total. You can try it yourself -with any date - you only need to remember the first two numbers to add to the square, then you've always got three of the four numbers you need to add one missing digit. You just need to remember that the centre left and centre right quadrants won't add up to the desired total, so don't use these. You just need to hope that your volunteer doesn't have a birthday in January or on the first of the month, otherwise you will have zeroes in the magic square. I'm sure Dr Benjamin has a way to get around this problem, but I'm nowhere near as clever as he is!

[@aaronhake601]

Who's the girl in the red scarf at 1:11? 😍

[@organic255]

59:30 😂😂😂

[@vijayaratnampurushowththam2342]

jan to december are u serious those numbers right,

[@pinolazerat65]

It isnt just bad that kids dont receive this method of math. But the thing that is down right criminal and treason is to punish kids for not having "the calculation" forcing kids to use the worst system, DESPITE finding a better method to get the answer on their on. Schools are there to make ppl conform and with out taught.

[@furqanmalik1799]

Ourd main

[@vuongquoc1981]

can anyone explain at 49:34 how can he knows the 4744? I can't get his idea

[@MinhNguyen-pb5ll]

Thanh phan tan You don't have to subtract from 4872 because doubling 4872, then subtracting 5000 could give you 4744 much faster than subtracting 128 from 4872 mentally. Since 4872 rounds up to the nearest thousand of 5000 (three zeros), you can make things a little easier by just doubling 872 (last three numbers from 4872) to make 1744. and replace 872 with 744 to get 4744. He explains the same concept at 47:00 but with a 3 digit number. That should make it easier to look at.

[@Andrew17921]

ridiculous ........ !!!!

[@elielsaf3362]

Not only he is a distinguished professor, but he's also a brilliant entertainer. He has a course called secrets of the mental math available on the great course website