Chance is also known as probability, which is represented numerically. Probability as a number lies between 0 and 1 . A probability of 0 means that the event will not happen.
For example, if the chance of being involved in a road traffic accident was 0 this would mean it would never happen. You would be perfectly safe. A probability of 1 means that the event will happen. If the probability of a road traffic accident was 1 there would be nothing you could do to stop it. It will happen.
In practice probabilities associated with everyday life events lie somewhere between 0 and 1. A probability of 0.1 means there is a 1 in 10 chance of an event happening, or a 10% chance that an event will happen. Weather forecasters might tell us that there is a 70% chance of rain.