156 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: Find an Entry of a 2x2 Matrix's Inverse
How the beat teaches it: Every slot gives a 2x2 matrix A with determinant 1, so its inverse has whole-number entries: A⁻¹ = [[d,-b],[-c,a]]. Find the absolute value of the (1,2) entry. Build that many notes anywhere in the kit.
This is lesson 7 of 24 in RockBlocks Math, Linear Algebra, a free course where every lesson turns a math idea into something you can count, hear, and play. The previous lesson, “Determinant of a 3x3 Matrix,” covered compute a 3x3 Determinant by Cofactor Expansion. Next is Lesson 8, “Solving Ax = b With the Inverse Matrix.”
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.