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.

🎵 Grade 2 Lesson 6: Building Fluency: Sums and Differences Within 20 — Fluency Within 20 (2.OA.B.2) mess around all you want, nothing here saves
90 BPM
Loading drum sounds…
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
4/4 ×2
🎯 Lesson: 0/4 · 🥁 0 solved · 0 badges

Grade 2, Lesson 6: Building Fluency: Sums and Differences Within 20

Math skill: Fluency Within 20 (2.OA.B.2)

How the beat teaches it: Every slot is a fast fact, addition or subtraction — build the answer in one row.

This is lesson 6 of 23 in RockBlocks Math, Grade 2, a free course where every lesson turns a math idea into something you can count, hear, and play. The previous lesson, Repeated Addition & Arrays,” covered repeated Addition & Arrays (2.OA.C.4). Next is Lesson 7, Place Value: Hundreds, Tens, and Ones.”

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.