Willie had some paper with which to make note cards. on his way to his room he found four more pieces to use. in his room he cut each piece of paper in half. when he was done he had 24 half-pieces of paper. with how many sheets of paper did he start ?

When you cut something, it doubles, in this question. So to retrace our steps, starting at 24, we divide by 2 (to reverse the cutting), then we subtract 4. 24/2=12.
12-4=8
He started with eight pieces of paper.

Check
8+4=12
12(2)=24.

Willie started with 8 pieces of paper.
Hope this helped :)

There are 15 rings on the laddey