What tells you how old a tree is?

Question

What tells you how old a tree is?

Answer 1

If it's a tree that's been chopped down, the common belief is that each ring you see in the grain on the top of the stump equals one year.

Answer 2

or, if you remember the date you planted the seed from which the tree grew, that's another way...  then again, if you write that stuff down, you're on you're way to becoming a nerd...  

;-)

Answer 3

[Answer: If you cut the tree and count the number of rings it has inside the stem of the tree (trunk), the number of rings is equivalent to the age of the tree.]