PROTOTYPE — Architect's Scale Simulator, second build in Weights & Measures. Reuses Ruler Simulator's Learn/Practice chassis and grading pattern. One simplification from the real tool: the "Which Scale?" question type is a direct multiple-choice pick rather than a full rotate-then-read chain — flagged for review before wiring into hil-shell/session-logger.

ARCHITECT'S SCALE

Six edges, eleven scales, one triangular tool — the instrument that reads a floor plan back into real feet
Tap a face to rotate the scale in your hand — same tool, three faces, six edges.
Why this tool exists: a house doesn't fit on a sheet of paper at real size. An architect's scale lets you draw (or read) a building at a fixed reduction — "1/4 inch on the paper equals 1 foot in the real house" — without doing that division in your head for every single measurement.
The trick that makes it fast: most of the edge is marked off in whole feet, evenly spaced at that scale's ratio. But look just to the left of the zero mark — that short stretch is subdivided into inches, and it's numbered backward (12 down to 0). That's on purpose: it lets you read "feet, then inches" in one motion — whole feet to the right of zero, then swing left into the inch stretch for the leftover. No mental math, no dividing a foot by hand.
Two scales share every edge. 1/4"=1'-0" and 1/8"=1'-0" live on the same physical edge, numbered in opposite directions — because 1/8 is exactly half of 1/4, the same tick marks serve both if you just read from the other end. That's why there are only six edges for eleven scales.
The one edge that isn't a scale at all: Face 3's second edge is just a normal ruler, divided into 16ths of a real inch — the "Full" edge. It's there for when you need to measure the actual paper, not the building.

You could measure a drawing in inches and multiply by the scale factor every time — but that's slow, and it's one extra place to make an arithmetic mistake on a jobsite or over a drafting table. The architect's scale moves that division into the tool itself, done once by the manufacturer, so every reading you take is already in real feet-and-inches. It's the same idea as a lookup table: pay the computation cost once, read the answer forever.

The reversed first foot is the same efficiency trick applied to the remainder. Without it, you'd read the nearest whole foot, then have to subtract to find the leftover inches. With it, the leftover is already sitting right there, pre-subtracted, the instant you swing your eye left past zero.