Word problem: A long strip of paper was folded in half

[Guest]

A long strip of paper was folded in half, then folding in half again. It then had 3 crease lines in the strip. If the paper was folded in half six more times (eight altogether), how many creases would there be when it was unfolded?

Note: When unfolded all the crease lines should be parallel to each other.

 

[Mrspi]

A long strip of paper was folded in half, then folding in half again. It then had 3 crease lines in the strip. If the paper was folded in half six more times (eight altogether), how many creases would there be when it was unfolded?

Note: When unfolded all the crease lines should be parallel to each other.

When in doubt, TRY IT OUT.

I took a sheet of typing paper, and began folding it in half, lengthwise. Here's what I found (before it got impossible to fold any more!):

1 fold gave 1 crease
2 folds gave 3 creases
3 folds gave 7 creases
4 folds gave 15 creases

Ok...now look carefully at these numbers and see if you can find a pattern. (Hint: consider powers of 2).

I hope this helps you.