Materials:
2 candles
1 glass container
matches
(Note: Have an adult with you)

Light the two candles. Cover one of the candles with the glass container. Wait to see which one burns out first.

Conclusion
The candle withe the glass lid over it burned out first. The candle burned out quicly because it used up all the oxygen in the glass container. The candle with no container over it had a lot more oxygen.