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Grains of rice on a chess board

There is a story about the inventor of chess being rewarded by putting 1 grain of rice on the first square of the board; 2 on the second and so on.  How much rice does that come to?


The total number of grains is 1.84467440737096E+19


At 25mg per grain thats 461168601842739 kilogrammes of rice


Which in more understandable terms is:


461,168,601,842.739 metric tonnes



453,886,749,619.642 tons


That’s a lot of rice


If you want to play around with the numbers the calculations are:


[double]$result = 0

1..64 |
foreach {
$square = [math]::Pow(2, ($psitem -1))
$result += $square


$wt = 0.025

$totalweight = ($wt * $result)/1000

$mtwt = $totalweight /1000

$tons = $totalweight * 0.00098421

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