144 BPM
Loading drum sounds…+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
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: Compute Var = (b-a)² ÷ 12
How the beat teaches it: Every slot gives a uniform distribution [0,b] where b is a multiple of 6 (which keeps the variance a whole number) — apply the formula (b-a)²÷12. Build that many notes anywhere in the kit.
This is lesson 15 of 24 in RockBlocks Math, Probability, a free course where every lesson turns a math idea into something you can count, hear, and play. The previous lesson, “Mean of a Continuous Uniform Distribution,” covered compute the Mean (a+b)/2. Next is Lesson 16, “Size of a Joint Sample Space.”
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.