1991 AMC 8 Question 16

When I follow the steps in the question, I first get rid of the top half. Then for step two, I get rid of the bottom row, which leaves me the third row. Then after the third step, I get rid of the right two numbers in row three. That leaves me only 9 and 10 after step three. Following the same logic and similar way of folding, why is the answer 9 instead of 10 when I fold over the left half?

Wow this question has been sitting around for a long time. If anyone knows how to do this, pls help ASAP.

Hi! This is a very interesting question, and I'm not really sure how to do it, but when I cut the picture out and played with it, I seemed to get 9 too.
I think it's because when you do Step 1, you don't get rid of the top half, instead, what remains is the top half.
(BTW: I labeled both sides of the paper with the numbers. so like, on the back of the 1 I wrote another 1.)Same for Step 2, I think. What you get is the bottom row.
For Step 3, I get 12 and 11 from the third row.
And lastly, for Step 4, I get 9.

Thanks for the explanation. I guess I didn’t think that the card had numbers on both sides. But it makes sense now.