1 ri is equal to the product of 12960 shaku multiplied by (10 over 33) (meter per shaku) and then (43.2 over 11) kilometers and then 3.9 kilometers (the part of overbar is a recurring decimal) because 1 shaku has been fixed as (10 over 33) meters.
1尺＝(10/33)mと定められたので、1里＝12960尺×(10/33)(m/尺)＝(43.2/11)km＝3.9km（上線部は循環小数）となる。