What actually is probability?
If you were to give the chance of something happening a number, that would be probability. The bigger the number? The more likely something is to happen.
Probability for Kids
Example
When you flip a coin, the probability of heads is 50%. The probability of tails? It's also 50%.
Because they have the same probability, what do you think will happen? You can try it for yourself. Flip a coin 100 times, what will happen? It will, most likely, land on Heads and Tails almost equally.
Rock Paper Scissors
When you play "Rock Paper Scissors", there are three things that could happen. That makes each option's probability 33%, or their fraction 1/3.