# Probability scale

A number from 0 to 1 showing how likely something is. 0 means impossible, 1 means certain and 1/2 means even chance.

Maths (school) · Part 08: Probability and statistics · Card 1 of 8 · Last updated 2026-10-19

## Analogy

Like a weather forecast dial from 'never' to 'definitely'.

## Example

**Fair six-sided dice**

P(6) = 1/6
P(even) = 3/6 = 1/2
P(7) = 0

## In practice

A 0.2 chance of rain means rain is unlikely but possible.

## Practice

### Flashcards

- **What is the probability of an even number on a fair dice?** 1/2, since 3 of the 6 numbers are even.

## Questions people ask

### How do you work out a probability?

Divide the number of ways your event can happen by the total number of equally likely outcomes. For rolling an even number on a dice, there are 3 even numbers out of 6, so the probability is 3/6 = 1/2.

### Can a probability be bigger than 1?

No. A probability of 1 means the event is certain. You cannot be more than certain. Probabilities run from 0 to 1, as a fraction, decimal or percentage. If you get an answer over 1, you have made an error.

## Related concepts

- [Relative frequency](https://studyvisually.com/learn/science/maths-school/maths-school-part-8/maths-school-part-8-concept-2)
- [Mutually exclusive events](https://studyvisually.com/learn/science/maths-school/maths-school-part-8/maths-school-part-8-concept-3)
- [Independent events](https://studyvisually.com/learn/science/maths-school/maths-school-part-8/maths-school-part-8-concept-4)
- [Tree diagrams](https://studyvisually.com/learn/science/maths-school/maths-school-part-8/maths-school-part-8-concept-5)

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