Stage 32 · Counting, Permutations, Combinations & the Binomial Theorem
32.1.4 'Cases' or 'Steps'?
32.1 The Two Counting Principles: Where All Counting Begins
Point 4 of 6
32.1.4 'Cases' or 'Steps'?
Core ideaIf one choice finishes the job, add; if it takes a relay of choices to finish, multiply — the whole question is whether the task is an 'or' or an 'and'
Module goal. Build the two basic habits of mind — add when you sort into kinds, multiply when you go step by step — and learn to tell whether a task is a 'sort' or a 'sequence', laying the foundation for permutations and combinations