In Year 1 Mathematics, it's super important to understand how to calculate probability.

So, what is probability?

Probability is a way to measure how likely something is to happen.

We show it as a number between 0 and 1:

• A probability of 0 means it can't happen at all.
• A probability of 1 means it will definitely happen.

Basic Formula

Here’s the simple formula for finding probability:

$$P(E) = \frac{\text{Number of outcomes we want}}{\text{Total number of possible outcomes}}$$

• In this formula, $P(E)$ is the probability of event $E$ happening.
• The top part (numerator) tells us how many times the event we want can happen.
• The bottom part (denominator) tells us how many total outcomes there are.

Ways to Calculate Probability

1. Classical Probability: This idea assumes that all outcomes have the same chance of happening. For example, when you roll a fair six-sided die, the chance of rolling a 3 is:

$$P(3) = \frac{1}{6}$$

This means you have one way to get a 3 out of six possible numbers.

2. Relative Frequency: This method uses real data from experiments or observations. For instance, if something happens 20 times out of 100 tries, the probability is:

$$P(E) = \frac{20}{100} = 0.2$$

This means there is a 20% chance of that event happening.

Conclusion

When you understand these formulas, you can better grasp how to measure uncertainty. This lays the groundwork for learning more complicated math concepts later on!