experiment failed. the 21 spells of domesius. the draw of seven

i had my wife think of a number between 1 and 7, then i wrote each number on a little square piece of paper and put them around the candle and then i stood over the candle and blew it out. the piece of paper that blew farthest away from the candle is supposed to be the answer for me. the number i drew was 5. my wifes number was 7. i think i did the experiment 3 times and never drew her number.
after i drew the first or second paper i thought in my mind that she maybe thought of the number 7 and it turned out after drawing like 3 pieces of paper i asked her if it was 7 and she said yes.
but the experiment as described failed. maybe its not supposed to be used like that?