Tree diagrams, the product rule and independent events
Grow tree diagrams to count outfits and race results, write probabilities on the branches, multiply along a path, add paths, and see what changes when the bead is not put back.
📖 Start here: read the steps of the “Lesson” in order (1, 2, 3 …) and answer each question. Then continue with “Practice”.
- UK: Year 10
- France: grade 10
- Germany: grade 8
- Iran: grade 10
- Afghanistan: grade 8
- Syria: grade 9
- Palestine: grade 9
- Ukraine: grade 9
- Russia: grade 8
Guide
This studio follows the counting and probability chapters of Iran's Year 10 ("counting without counting", the product rule for counting), Afghanistan's Year 8 (the tree diagram and the first rule of paths, the product) and Year 9, and GCSE tree diagrams and frequency trees in England.
Your child grows a tree by tapping + on a point, or by choosing which branches grow. Tapping a ? on a branch opens a box under the diagram to write a fraction. Leaves can be tapped to choose the outcomes of an event.
Common mistakes this studio works on: adding the choices (3 shirts and 2 trousers make "5" outfits), adding along a branch instead of multiplying, branch probabilities that do not add up to 1, forgetting that the second draw changes when the bead is not put back, and thinking a coin "remembers" the first toss.