LIT DOUBLER keeps an addend only when the left column is odd, then halves the left and doubles the right. For 47 by 13 the kept addends are 13, 26, 52, 104, and 416. Five adds are kept. Six wrong offers are dropped, including the even row 208. The kept addends sum to 611, and adding 13 repeatedly, 47 times, also makes 611. The law sums to 611. A second run must match.
AMBER Doubling and halving is called Russian peasant multiplication. The name is assigned.
WALL This page multiplies 47 by 13. It does not time the method, and it does not speak for every other product.
MODEL One pupil. Five stones stand for the five kept addends. The even offer is not given a stone. No cartridge is loaded.
Checking the notary.
Seal sha256(name|slug|blurb): b79db9c84442939de51084ac4755dc47c71339c3235647466808570ade280f4a