StackCalc Learning Lab
The Learning Lab is the first physical teaching-resource collection in the StackCalc ecosystem. It gives a learner tangible ways to represent quantities, a four-register stack, an expression tree, and coordinate relationships before translating them into calculator operations.
The internally maintained collection contains 13 STL plates with 79 solids, matching OpenSCAD sources, laser artwork, a catalog manifest, reference cards, and a teacher booklet. The public release below contains the printable STL plates and teacher PDFs.
The first page of the printable teacher guide labels the four connected investigations. The pictured boards are teaching representations, rather than unengraved STL previews.
The first collection
| Resource | What it makes visible |
|---|---|
| Fraction studio | A quantity, its whole, numerator, and denominator before an RPN fraction entry. |
| Stack stage | Four value tiles arranged as X, Y, Z, and T, so ENTER, stack lift, and binary operations have a physical model. |
| Expression tree | Seven removable tokens for reading an expression in postorder before keying the resulting RPN sequence. |
| Coordinate lab | A 10 × 10 point grid and locator pegs for measuring a 3-4-5 triangle and checking a distance calculation. |
| Pocket cards | Compact references for stack, fractions, and distance exercises. |
A common calculation model
The calculator, apps, and Learning Lab share a single premise: values arrive before the operation that consumes them. The Learning Lab turns that sequence into a question a learner can inspect: what goes on the stack now, and what two values will this operation use?
The fraction studio uses blocks with a common 24 × 24 mm footprint. Whole, half, third, quarter, sixth, and eighth blocks are 96/n mm tall, so equivalent towers meet at the same height. The stack stage is a 158 × 164 mm board with four reusable value tiles. The expression-tree board is 196 × 164 mm with tokens for a, b, +, c, d, -, and *. Those are design facts about the supplied prototype; they do not demonstrate learning outcomes.
The printable reference cards label the stack, fraction, and distance activities used with the STL plates.
Prototype status
The Learning Lab is ready for printing and teacher review. The calculator is an unpowered four-part mechanical prototype, and its RP2350 PCB is in fabrication. We will add fit, engraving, and educator findings as they are collected.
Download the prototype materials
The 0.2.0 STL pack is the canonical printable release of the Learning Lab. It contains the 13 STL plates only; the teaching cards and teacher booklet are provided separately as PDFs. Source code, CAD generators, and manufacturing artwork are not part of this public download.
| File | Contents |
|---|---|
| Learning Lab STL pack 0.2.0 | The 13 printable STL plates for the first collection. SHA-256: b0dc8ecd980a4760ca1bd5c9038d93ff23a29736937eb6bf7017881926908fa1 |
| Reference cards — Letter | Printable stack, fraction, and distance cards for US Letter paper. |
| Reference cards — A4 | Printable stack, fraction, and distance cards for A4 paper. |
| Teacher booklet — Letter | Eight-page investigation guide and worksheet for US Letter paper. |
| Teacher booklet — A4 | Eight-page investigation guide and worksheet for A4 paper. |
Read the related engineering notes: