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.

🎵 Kindergarten Lesson 21: Making Teen Numbers — Composing Teen Numbers (K.NBT.A.1) mess around all you want, nothing here saves
78 BPM
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Kindergarten, Lesson 21: Making Teen Numbers

Math skill: Composing Teen Numbers (K.NBT.A.1)

How the beat teaches it: Every slot adds a small number onto 10 — any number from 11 to 19 is a 'teen' number made from 10 plus some ones.

This is lesson 21 of 24 in RockBlocks Math, Kindergarten, a free course where every lesson turns a math idea into something you can count, hear, and play. The previous lesson, More Subtracting Within 10,” covered subtraction Within 10 (K.OA.A.2). Next is Lesson 22, Teen Numbers: 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.