Fresh arithmetic puzzles for worksheets and classroom apps
Arithmetic practice works better as a puzzle. Each call gives a levelled puzzle and its solution, so a worksheet and its answer key come from the same request.
How education teams use Sumbloom API
- Pick a type and level: easy 4x4 Cage Grids for younger pupils, 6x6 for stronger ones.
- Call /v1/puzzle.svg for the worksheet and add solution=true for the answer key.
- Use a seed per class or per day so every pupil gets the same puzzle.
Brick Pyramids practise addition and, at hard level, simple algebra; Target puzzles practise all four operations.
For ready-made printables, the Sumbloom Puzzle Book has 120 puzzles with answers.
Three real API responses (seed "demo"), shortened
| Request | Puzzle | Solution |
|---|---|---|
| /v1/puzzle?type=target&level=easy&seed=demo | Numbers 3, 6, 6, 7, 7, 15; target 28 | 7 + 6 = 13; 15 + 13 = 28 (one valid route) |
| /v1/puzzle?type=cage&level=easy&seed=demo | 4x4 grid, 7 cages: 8+, 1−, 2÷, 12×, 5+, 7+, 1− | rows 1243 / 3124 / 2431 / 4312 (unique) |
| /v1/puzzle?type=pyramid&level=medium&seed=demo | 5 rows; bottom row 3, ?, ?, 7, ? | bottom 3, 10, 10, 7, 10; top 141 (unique) |
Source: Output of the API's own code (products/sumbloom-book/api/worker.js pick + toPuzzle over its solver-checked puzzle bank) run with node on 10 Oct 2026; the live endpoint returns the same puzzle for the same seed.
FAQ
Do I need a key for a class?
Not for up to 50 puzzles a day; a Starter key covers 10,000 a month.
Are answers checked?
Yes, every Cage Grid and Brick Pyramid in the bank has exactly one solution, checked by a solver.
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