Grade 6: Probability

Warm up with a quick recall on the board. Order events from impossible to certain in everyday language, then quantify simple chances as fractions of the equally-likely outcomes.

Probability measures how likely an event is, from impossible to certain. Students first describe chance in words (impossible, unlikely, even chance, likely, certain), then put it on a 0 to 1 scale, and finally write simple probabilities as fractions: favourable outcomes over the total number of equally likely outcomes. Model the method clearly, thinking aloud:

• Start with everyday language and order the words on a line from impossible (0) to certain (1), with even chance in the middle.
• Use fair, equally likely situations first: a coin, a dice, a spinner with equal sections.
• Count outcomes: the probability of an event is the number of favourable outcomes over the total number of equally likely outcomes.
• Show a probability is a fraction from 0 to 1, and that all the outcomes' probabilities add to 1.
• Compare theory with experiment: predict, then roll or spin many times and watch the results settle near the prediction.

Work this through step by step on the board, then have the class talk you through a second one.

• Chance of rolling a 4 on a fair dice:
• favourable outcomes: 1 (just the 4)
• total outcomes: 6
• probability = 1/6

Do the first few questions of the practice worksheet together, one child explaining each step. Check for understanding before releasing the class to work alone.

Students complete the worksheet independently. Hand out the three difficulty levels below so every child works at the right stretch.

Circulate and look for these, they are the usual sticking points:

• Thinking every event is 50/50 because there are two results (rain or no rain is not even).
• Counting outcomes that are not equally likely as if they were.
• Writing a probability bigger than 1, or as a whole number.
• Believing a run of heads makes tails 'due' on the next fair toss.
• Assuming a rare-but-possible event is impossible, and thinking past results change the next independent outcome.

Pull the class back together. Ask one child to explain probability in their own words, pose a single check question everyone answers on a mini whiteboard, and name what you will build on next lesson.

Use the independent worksheet as the evidence. A child who can complete it accurately and explain one answer has met the objective; anyone who cannot needs the easier level and a short reteach next session.