Ask your class what "likely" means as a percentage and you'll probably hear anything from 50% to 100%. That spread is where this resource starts. Chance words aren't exact, which is why we use numbers from 0 to 1. It opens on a TV weather forecast board (what does a 70% chance of rain mean?).

How it runs

Three lessons of 45–60 minutes. After the weather board and warm-up, teach the probability scale and have students sort 10 event cards onto it. Suggested placements are on the slides, but expect arguments about the middle of the scale. Then run the "how likely is likely?" survey, where each student marks what likely means to them, and graph the class results at 2 students per line.

Lesson 2 is equally likely outcomes. Students list the outcomes of simple experiments, write each probability as a fraction and check the probabilities add to 1. They solve the Case of the Faded Prize Spinner and decide whether the canteen lucky dip is worth the money. The memory game comes last, on the slides as a whole class or in groups with the printable cards.

Maths covered

• MA3-CHAN-01: describe probabilities from 0 to 1, discuss the imprecise meaning of chance words, list equally likely outcomes, write probabilities as fractions and show they add to 1, and match benchmarks such as ½, 0.5 and 50%
• MA3-DATA-01: draw a column graph with a many-to-one scale of the class chance-word survey

Good to know

• "Sample space" and complementary events are Stage 4, so they are not used.
• Print memory cards on light card, one set per group.
• Refreshed from my 2021 Probability Interactive Memory Game for the 2022 NSW syllabus.
• Maths Detectives characters and Keynote fonts included.