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Stage: 2 Challenge Level: 
In the forest there is a Deca Tree.
A Deca Tree has $10$ trunks,
and on each trunk there are $10$ branches,
and on each branch there are $10$ twigs,
and on each twig there are $10$ leaves:
One day a woodcutter came along and cut down one
trunk from the tree.
Then he cut off one branch from another trunk of the tree.
Then he cut off one twig from another branch.
Finally he pulled one leaf from another twig.
How many leaves were left on the tree then?
Click here for a poster of this problem.
NRICH is part of the family of activities in the Millennium Mathematics Project.