Comments on: The Rice and the Chessboard – how the Internet has ruined life for the better http://www.stupidstupidity.co.uk/2009/08/23/the-rice-and-the-chessboard-how-the-internet-has-ruined-life-for-the-better/ Richie G: established 1986 Mon, 14 Jun 2010 02:53:51 +0100 hourly 1 http://wordpress.org/?v=3.0 By: Richie G http://www.stupidstupidity.co.uk/2009/08/23/the-rice-and-the-chessboard-how-the-internet-has-ruined-life-for-the-better/comment-page-1/#comment-3067 Richie G Thu, 25 Mar 2010 20:37:53 +0000 http://www.stupidstupidity.co.uk/?p=135#comment-3067 I don't recall getting any homework when I was 10 years old... and that was only 14 years ago! For the question I was given, your answer is incorrect I'm afraid. There are indeed 9,223,372,036,854,775,809 grains on the board, but it is that number in the last box on the board (the 64th one) only. The question - and the hypothetical situation in which the question originated from - was to find the number of grains on the <em>whole</em> board, not just the last box. Therefore, the answer to the question I was given is (9223372036854775809^2)-1. (By the way, I know the brackets I've put in there are supurflous, but they help me out when I'm using ^ for powers instead of little itsy digits!) At the risk of sounding cocky, you might want to check what the exact question your child is being asked - whether it is the total number of grains on the board or just the number of grains in the 64th square. I don’t recall getting any homework when I was 10 years old… and that was only 14 years ago!

For the question I was given, your answer is incorrect I’m afraid. There are indeed 9,223,372,036,854,775,809 grains on the board, but it is that number in the last box on the board (the 64th one) only. The question – and the hypothetical situation in which the question originated from – was to find the number of grains on the whole board, not just the last box. Therefore, the answer to the question I was given is (9223372036854775809^2)-1. (By the way, I know the brackets I’ve put in there are supurflous, but they help me out when I’m using ^ for powers instead of little itsy digits!)

At the risk of sounding cocky, you might want to check what the exact question your child is being asked – whether it is the total number of grains on the board or just the number of grains in the 64th square.

]]> By: Rob http://www.stupidstupidity.co.uk/2009/08/23/the-rice-and-the-chessboard-how-the-internet-has-ruined-life-for-the-better/comment-page-1/#comment-3066 Rob Thu, 25 Mar 2010 19:34:11 +0000 http://www.stupidstupidity.co.uk/?p=135#comment-3066 given that you only have 1 grain on square one then the answer should be 1+2^63 = 9223372036854775809 - how do i know this??? it was my 10 year olds homework tonight!! - seems like maths is getting harder at school given that you only have 1 grain on square one then the answer should be 1+2^63 = 9223372036854775809 – how do i know this??? it was my 10 year olds homework tonight!! – seems like maths is getting harder at school

]]> By: Richie G http://www.stupidstupidity.co.uk/2009/08/23/the-rice-and-the-chessboard-how-the-internet-has-ruined-life-for-the-better/comment-page-1/#comment-2254 Richie G Wed, 25 Nov 2009 20:54:20 +0000 http://www.stupidstupidity.co.uk/?p=135#comment-2254 OK, I worked out (ish) where I went wrong... 7x7 is 49 not 42... Oh, how foolish of me... OK, I worked out (ish) where I went wrong…

7×7 is 49 not 42…

Oh, how foolish of me…

]]> By: Richie G http://www.stupidstupidity.co.uk/2009/08/23/the-rice-and-the-chessboard-how-the-internet-has-ruined-life-for-the-better/comment-page-1/#comment-2253 Richie G Wed, 25 Nov 2009 20:35:40 +0000 http://www.stupidstupidity.co.uk/?p=135#comment-2253 Ah I get it - so you have the 1x1 squares, 2x2 squares, 3x3 squares etc. There are, of course, 8x8=64 available 1x1 square squares, working right down to 2x2=4 available 7x7 square squares on the board, and of course the 1 (or 1x1=1 for completeness) 8x8 square. So, you have the square numbers: 1x1=1 2x2=4 3x3=9 4x4=16 5x5=25 6x6=36 7x7=42 8x8=64 Adding them all up, you have 1+4+9+16+25+36+42+64 = 197 Ah, I'm missing some somewhere if you got 204... Ah I get it – so you have the 1×1 squares, 2×2 squares, 3×3 squares etc.

There are, of course, 8×8=64 available 1×1 square squares, working right down to 2×2=4 available 7×7 square squares on the board, and of course the 1 (or 1×1=1 for completeness) 8×8 square.

So, you have the square numbers:
1×1=1
2×2=4
3×3=9
4×4=16
5×5=25
6×6=36
7×7=42
8×8=64

Adding them all up, you have
1+4+9+16+25+36+42+64 = 197

Ah, I’m missing some somewhere if you got 204…

]]> By: Martyn Smith http://www.stupidstupidity.co.uk/2009/08/23/the-rice-and-the-chessboard-how-the-internet-has-ruined-life-for-the-better/comment-page-1/#comment-2248 Martyn Smith Tue, 24 Nov 2009 01:47:34 +0000 http://www.stupidstupidity.co.uk/?p=135#comment-2248 no its much deeper than that, here's a hint the 8x8 square is a square it self therefore there is another the answer is 204, how did i come up wkth this answer and when you figure it out there is a deffinate pattern tha emmerges. 8x8 and 1x1 are a good start no fill in the gaps. no its much deeper than that, here’s a hint the 8×8 square is a square it self therefore there is another the answer is 204, how did i come up wkth this answer and when you figure it out there is a deffinate pattern tha emmerges. 8×8 and 1×1 are a good start no fill in the gaps.

]]> By: Richie G http://www.stupidstupidity.co.uk/2009/08/23/the-rice-and-the-chessboard-how-the-internet-has-ruined-life-for-the-better/comment-page-1/#comment-2247 Richie G Mon, 23 Nov 2009 18:18:50 +0000 http://www.stupidstupidity.co.uk/?p=135#comment-2247 Well, as mentioned above you will find that there are 64 squares on a chess board. I'm not entirely sure what you mean by pattern within the answer. Obviously it's an 8x8 square which are half white half black (32 of each). If you want to put items on the board without any on the diagonal or the straight lines you use the move that the Knight (or 'horsey' if you will) uses whilst playing Chess. Other than that, I don't know what patterns you might be referring to... Well, as mentioned above you will find that there are 64 squares on a chess board. I’m not entirely sure what you mean by pattern within the answer. Obviously it’s an 8×8 square which are half white half black (32 of each). If you want to put items on the board without any on the diagonal or the straight lines you use the move that the Knight (or ‘horsey’ if you will) uses whilst playing Chess.

Other than that, I don’t know what patterns you might be referring to…

]]> By: Martyn Smith http://www.stupidstupidity.co.uk/2009/08/23/the-rice-and-the-chessboard-how-the-internet-has-ruined-life-for-the-better/comment-page-1/#comment-2242 Martyn Smith Sat, 21 Nov 2009 17:00:18 +0000 http://www.stupidstupidity.co.uk/?p=135#comment-2242 Also how many squares are on a chess board and what is the pattern within the answer? try this without the aid of the internet, cos i did this in primary school and am sure you'll get it fairly easily!! sorry about all the maths questions i just like them, there fun, hehe. Also how many squares are on a chess board and what is the pattern within the answer?
try this without the aid of the internet, cos i did this in primary school and am sure you’ll get it fairly easily!!

sorry about all the maths questions i just like them, there fun, hehe.

]]> By: Martyn Smith http://www.stupidstupidity.co.uk/2009/08/23/the-rice-and-the-chessboard-how-the-internet-has-ruined-life-for-the-better/comment-page-1/#comment-2241 Martyn Smith Sat, 21 Nov 2009 12:41:22 +0000 http://www.stupidstupidity.co.uk/?p=135#comment-2241 hehe, thats briliant, however, i found it easier to say that is is 2 to the power of 64 (the number of chess squares, raised to the binary seqence, which is obviously 2, (0,1)) = 18 446 744 073 709 551 616 then take the square root which is = 4 294 967 296. therfore you are right, how ever the numbers would be read; eighteen-pentillion, four-hundred and forty-six-quadrillion, seven-hundred and fourty-four-trillion, seventy-three-billion, seven-hundred and nine-million, five-hundred and fifty-one-thousand, six-hundred and six-teen. this way is the most common way of saying the number, however Richie and I know you this is the american way so for you, (and me) in proper english would be read; eighteen-trillion, four-hundred and forty-six-thousand, seven-hundred and forty-four-billion, seventy-three-thousand seven-hundred and nine-million, five-hundred and fifty-one-thousand, six-hundred and six-teen. therfore you are right. Also for compleateness, the square number is read; four-billion, two-hundred and ninty-four-million, nine-hundred and sixty-seven-thousand, two-hundred, and ninty-six. and in proper english; four-thousand-two-hundred and ninty-four-million, nine-hundred and sixty-seven-thousand, two-hundred, and ninty-six. try this for fun I have the answer, and i dont mind if you use the internet to help you. Twenty-seven identical white cubes are assembled into a single cube, the outside of which is painted black. The cube is then disassembled and the smaller cubes thoroughly shuffled in a bag. A blindfolded man (who cannot feel the paint) reassembles the pieces into a cube. What is the probability that the outside of this cube is completely black? hehe, thats briliant, however, i found it easier to say that is is 2 to the power of 64 (the number of chess squares, raised to the binary seqence, which is obviously 2, (0,1))

= 18 446 744 073 709 551 616 then take the square root

which is = 4 294 967 296.

therfore you are right, how ever the numbers would be read;
eighteen-pentillion, four-hundred and forty-six-quadrillion, seven-hundred and fourty-four-trillion, seventy-three-billion, seven-hundred and nine-million, five-hundred and fifty-one-thousand, six-hundred and six-teen.
this way is the most common way of saying the number, however Richie and I know you this is the american way so for you, (and me) in proper english would be read;
eighteen-trillion, four-hundred and forty-six-thousand, seven-hundred and forty-four-billion, seventy-three-thousand seven-hundred and nine-million, five-hundred and fifty-one-thousand, six-hundred and six-teen.

therfore you are right.
Also for compleateness, the square number is read;
four-billion, two-hundred and ninty-four-million, nine-hundred and sixty-seven-thousand, two-hundred, and ninty-six. and in proper english;
four-thousand-two-hundred and ninty-four-million, nine-hundred and sixty-seven-thousand, two-hundred, and ninty-six.

try this for fun I have the answer, and i dont mind if you use the internet to help you.

Twenty-seven identical white cubes are assembled into a single cube, the outside of which is painted black. The cube is then disassembled and the smaller cubes thoroughly shuffled in a bag. A blindfolded man (who cannot feel the paint) reassembles the pieces into a cube. What is the probability that the outside of this cube is completely black?

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