Gurmit The Hermit Puzzle - Solution

The Puzzle:

Gurmit The Hermit
Gurmit Burmit is a hermit - he lives all on his own on a lonely desert island. There is sand all around him: in front of him, behind him and on both sides, as far as Gurmit can see. In fact all he ever eats is sandwiches.

One day Gurmit decided to count the grains of sand. He started off by scooping up two handfuls of sand from the ground. "THERE MUST BE A BILLION GRAINS HERE IN MY HANDS" he thought to himself.

Was he close? Would his hands hold a billion grains of sand, or more, or less?




Our Solution:

A billion grains is an awful lot of sand.

The way to make estimates of large numbers like these is to build them up from smaller amounts by multiplying.

First you can count 100 grains of sand and see how large a pile it makes. Put it in a teaspoon. Depending on how small the grains are you might find that 10 or 20 such small piles would fill a teaspoon.

So let us say that 2000 grains would fill a teaspoon.

Now let's imagine that Gurmit's hands will hold about 100 teaspoons of sand.

That is only 200,000 grains!

A billion is 1,000,000,000 grains. Enough to cover Gurmit from head to foot!


Puzzle Author: Stephen Froggatt

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