A Cuo () in China or sai in Japan is a unit of volume measurement.https://en.wiktionary.org/wiki/撮 One cuo equals 1⁄1000 sheng. It is 1 mL (millilitres) in China and 1.804 mL in Japan.
The word cuo () means (a) to pick up (e.g., salt) using one's fingertips, or (b) the small amount of something that can be picked up in this way.
China
+ Volume units effective since 1930 in ChinaPinyinCharacterRelative valueMetric valueUS valueImperial valueNotescuō1 mL0.0338 fl oz0.0352 fl ozmillilitresháo10 mL0.3381 fl oz0.3520 fl ozcentilitregě100 mL3.381 fl oz3.520 fl ozdecilitreshēng11 L2.113 pt1.760 ptlitredǒu1010 L21.13 pt2.64 gal17.60 pt2.20 galdecalitredàn100100 L26.41 gal22.0 galhectolitre
Japan Volume + Volume units in Japan Iwata, Shigeo. "Weights and Measures in Japan"UnitShōMetricUSImperialRomanizedKanjiExactApprox.ExactApprox.ExactApprox. Sai L 1.804mL cuyd 29.28min gal 30.47min 0.1101cuin Shaku L 18.04mL cuyd 0.6100floz gal 0.6349floz 1.101cuin Gō L 180.4mL cuyd 0.3812pt gal 0.3174pt 0.3276drypt Shō 1 L 1.804L cuyd 1.906qt gal 1.587qt 1.638dryqt To 10 L 18.04L cuyd 4.765gal gal 3.968gal 2.048pk Koku 100 L 180.4L cuyd 47.65gal gal 39.680gal 5.119buNotes: Approximations are rounded to four significant figures.
For more details, please see Sheng (volume)
See also Chinese units of measurement Japanese units of measurement :zh:中國度量衡
References