142 BPM
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4/4 ×2
Drag rhythmic values into up to 8 beat blocks per line to build a drum groove, or click a tile then click a block to place it — handy on a trackpad.
Math skill: Count Committees That Exclude One Specific Person
How the beat teaches it: Every slot asks for a committee of size r chosen from a group, but with one specific person excluded — count C(n-1, r), choosing from everyone except that one person. Build that many notes anywhere in the kit.
This is lesson 13 of 24 in RockBlocks Math, Discrete Math, a free course where every lesson turns a math idea into something you can count, hear, and play. The previous lesson, “Permutations (nPr),” covered compute nPr, the Number of Ordered Arrangements. Next is Lesson 14, “The Pigeonhole Principle.”
Every slot above (A, B, C, D) is its own question, and it’s a real, blank RockBlocks beat the whole time — the same drag-and-drop tiles, kit, tempo, sheet music, and drummer view as anywhere else on the site. Tap ❓ Questionin the corner to read the current slot’s problem, build your answer right in the grid, then tap ✓ Check Answerto grade it. Once you’re done, keep going: expand the beat, drop it into a Stack, or save a copy to your own page — nothing here overwrites the lesson itself, so every visitor still starts from the same blank slots.