Probability of picking two
There are 4 to 6 cards, cups, boxes, doors, envelopes or bags, labelled A, B, C and so on, and one or two of them hide a star, a coin or a prize. Two are picked at random. Every pair is listed on screen; the student ticks the ones that fit, then gives how many there are or the chance as a fraction.
Listing the pairs in order (AB, AC, AD, then BC, BD, then CD) means none is missed or counted twice. 'At least one', 'exactly one', 'both' and 'none' each pick out different pairs. Any equal fraction is accepted, so 5/15 and 1/3 are both right.
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What changes each time
- 4 to 6 things, so 6, 10 or 15 pairs
- One or two of them hiding something
- At least one, exactly one, both or none, as a count or a fraction
More data, graphs and probability practice
- Sort and count (Grade 1)
- Bar graphs (Grade 2)
- Reading pictographs (Grade 3)
- Line plots (Grade 3)
- Averages from a bar chart (Grade 3)
- Pie charts with percentages (Grade 4)
- Pie charts with numbers (Grade 4)
- Venn diagram problems (Grade 4)
- Probability with coins and dice (Grade 4)
- Does the coin remember? (Grade 4)
- True, false or no information (Grade 5)