You take out a lighter to light up a cigarette or candle. But the lighter doesn't work. You try several times but it simply does not burn. In an instant you change the lighter to a box of matches, take out a match and light your cigarette or candle.
Using this effect Tommy Wonder also teaches the pros and cons of approaching potential spectators with the question: "Do you want to see some magic?" Of course, he offers a much better alternative.