EXPERIMENT WITH TEN MATCHES
Lay ten matches side by side ([Fig. 7]) and request some one to lift each match singly, and passing it over two matches, cross a third match with it until there are five crosses on the table ([Fig. 8]). Two matches (and only two whether crossed or single) must be passed over at a time.
Fig. 7.
Fig. 8.
The secret is that No. 1 must be crossed first and No. 9 second, or the trick cannot be accomplished.
The following are the correct moves: 4 over 2 and 3 60 and crossed on 1; 6 over 7 and 8 and crossed on 9; 8 over 7 and 5, crossed on 3; 2 over the 3 and 5, crossed on 7; the 10 over the 9 and 7, crossed on 5.