[yiypbctc] Decimal divisions of a furlong

Even though it's not metric, powers of 10 do appear in some imperial units of length and area.

1 furlong = 10 chain = 1000 link
1 furlong^2 = 10 acre = 100 chain^2

1 Roman mile = 1000 (millia) strides (2 steps per stride). 5 yards in 5.68 steps. 7.04 yards in 8 steps.

1 mile = 8 furlong