# Flip a Coin 100 Times

We all have those friends who think they can predict the future. They tell us what we’re going to get for our birthday, how many children we’ll have, and if their favorite team will win. But you know what? We don’t need them! With this experiment, you too can become a fortune teller extraordinaire! All it takes is flipping a coin 100 times and interpreting the results of each flip.

## Flip a coin 100 times.

For each head record a “1” and for each tail record a “-1”. Then, total up all of the results.

Percentage of Heads = Total Number of 1’s / 100

Heads you have seen: _________  (Include +/- to give accurate percentage)

Tails you have seen: _________  (Include +/- to give accurate percentage)

MATH FORMULA EXPLANATION: 100 * (1 + -1) = 0.5

The more heads you have seen, the closer the percentage is to 50%. So if you flipped 20 heads out of 100 flips, you are close to 50%, or if you flipped 49 heads out of 100 flips, you are closer to 50%. This is because the percentage changes at every flip.

Good Luck and Have Fun!

Record the results in order, from 1 to 100.

Example: 1. Head 2. Tails 3-1 = -2 4-2 = -4 5-3 = -6 6-4 = -8 7-5 = -10 8-6 = -12 9-7 = -14 10. Head 11. Tails 12. Head 13… etc

Heads I have seen: 30 Tails I have seen: 70

Percentage of Heads = Total number 1 / 100 = -80 / 100 = 80%

Heads you have seen: _________  (Include +/- to give accurate percentage)

Tails you have seen: _________  (Include +/- to give accurate

### Count how many times heads come up versus tails and interpret.

If you saw over 60% heads, then you may be a great predictor of the future! If you saw 40% or fewer heads then your friends will never let you do this experiment again. You are most likely not a good predictor of the future.

You’ve done the experiment! Have fun telling your friends that you are a fortune-teller.

Percentage of Heads = Total number 1 / 100 = -52 / 100 = 52%

Heads you have seen: _________  (Include +/- to give accurate percentage)

Tails you have seen: _________  (Include +/- to give accurate percentage)

Percentage of Heads = Total number 1 / 100 = -18 / 100 = 18%

Heads you have seen: _________  (Include +/- to give accurate percentage)

Tails you have seen: _________  (Include +/- to give accurate percentage)

Heads I have seen: 11 Tails I have seen: 89

Percentage of Heads = Total number 1 / 100 = -88 / 100 = 88%

Heads you have seen: _________  (Include

Example: I saw 80% heads. I must be a good predictor of the future. My friends were so impressed!

I saw 11 heads and 89 tails out of 100 flips, meaning I am closer to 18%. This means that whatever happens to me in the future, it won’t always turn out as expected! Maybe for my next experiment, I should try flipping a coin 1000 times. What do you think?

### Please respond to the following questions:

• Why would somebody use this experiment?
• How can you tell if your results are accurate?
• Did your results change as you flipped more heads or tails? Why or why not?   I will try predicting the weather…Good Luck and Have Fun!

Heads I have seen: _________  (Include +/- to give accurate percentage)

Tails I have seen: _________  (Include +/- to give accurate percentage)

Percentage of Heads = Total number 1 / 100 = –