When a coin is tossed, there are two possible outcomes: "heads" and "tails" (ignoring the unlikely event that the coin lands on its edge). Each outcome is equally likely, so the chance of getting one or the other is 1 out of 2 (1/2). That is, if 1.0 is certainty and 0.0 is no chance, then the probability of one of the two outcomes is 0.5, or 50%.

Say you toss the coin twice and it comes up heads both times. If you toss the coin a third time, is it more likely to come up tails?
Answer

To explore the concept of probability, try tossing our "virtual coin." Collect some data: try tossing the coin 100 times. What do you think the percentages will be? Is there a certain minimum number of tosses you can make to guarantee that you will get exactly 50% heads and 50% tails?