Writing Probabilities as Fractions

Maths: KS3, topic 5.1.1

Probability tells us how likely an event is to happen.

• Look at the fair 4-sided spinner.

• The spinner has 4 sections in total (A, B(Green), B(Yellow), and C).

• This means the total number of outcomes is 4.

• Imagine we want to find the probability of landing on B.

• We need to count how many sections have a 'B' on them.

• There are 2 sections labelled B.

• This means our favourable outcomes = 2.

$Writing the fraction$

Let's put it all together for the spinner!

• Total sections = 4. Sections with 'B' = 2.

• Probability = Favourable ÷ Total

• The probability of landing on B is 2/4.

• We can simplify this fraction to 1/2.

Test yourself on Writing Probabilities as Fractions