I have some matchsticks set up like this: I + XI = X. If you do not know Roman numerals, here is a quick starter: I=1 II=2 III=3 IV=4 V=5 VI=6 VII=7 VIII=8 IX=9 X=10 XI=11 XII=12 XIII=13 XIV=14 XV=15...... Of course, I + XI = X is wrong. You are told to move the minimum number of matchsticks to make the question correct. So, how many do you have to move? -Riddles