I have got one assignment to calculate the approximate sum total of all cells in the human body. How to tackle this problem? I know that the current statistics is $10^{13}$ cells. I wanted some hints.

  • @kmm Actually I don't know where to start. – dexterdev Aug 24 '14 at 13:09
  • yes I calculated it by dividing the volumes. Volume of average human body / avg. volume of a mammalian cell. Around 10^14 cells. – dexterdev Aug 24 '14 at 13:56
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    So that's larger by only one order of magnitude. Not that bad for a rough approximation. – Hav0k Aug 24 '14 at 14:12

This is a classic Fermi estimation problem. The usual approach is to estimate the volume of a body, estimate the volume of a cell, and divide one by the other, remembering of course to have both volumes in the same units.

My quick attempt gave 1013 to the nearest order of magnitude.

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