x tile — the unknown numberunit token — worth 1ten-block — ten unitscoral with a bar — negativebeam — the equals sign
The beam hangs level because both pans weigh the same — that is exactly what the equals sign claims. Take something off the left and you must take the same off the right, or it tips. Ten units are bundled into one ten-block; if a quantity still will not fit in the pan, a single labelled token carries the number instead. Below, the same step is hung on both pans of a small beam, with the equation it produces set beside it. Coral tokens with a bar are negative units: each one cancels exactly one gold unit.