Understanding Probability

What is probability?

Probability is the chance or likelihood that something will happen.

It helps us answer questions like:

Will it rain tomorrow?

What are the chances of pulling a red marble from a bag?

Is it likely I’ll get heads if I flip a coin?

Probability is often written as:

Words (certain, likely, unlikely, impossible),

Fractions (1/2 chance of heads),

Percents (50%),

Numbers between 0 and 1 (0 = impossible, 1 = certain).

How do we measure probability?

Probability is written as a number between 0 and 1:

0 means the event is impossible (can’t happen).

1 means the event is certain (will definitely happen).

½ means it’s equally likely or unlikely.

Probability as a fraction or ratio

You can calculate probability using this formula:

Probability equation

For example, if you roll a die, what’s the probability of rolling a 3?

Probability example

Examples in real life math

Flipping a coin: 1 out of 2 chance of heads = ½

Picking a marble: 3 red marbles out of 10 total = 3/10

Drawing a card: 4 queens in a 52-card deck → 4/52 = 1/13

Why probability matters

It helps students understand chance and fairness (e.g. in games).

It connects to fractions, decimals, percentages.

It supports data analysis and prediction.

It prepares them for statistics later in school.

Probability worksheets

We have two sets of worksheets for grade 4 and grade 5 students to work on simple probability.

Grade 4 probability worksheets

In these worksheets students are introduced to simple probability questions.

Grade 5 probability worksheets

In these worksheets, students determine the probability of certain events and express them as a fraction.

Probability worksheet
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