Tā yòng gǎnchèng chēng le yíxià zhè dài mǐ, zhènghǎo shí jīn.
He weighed the bag of rice on the steelyard: exactly ten jin.
Tips
culture
A steelyard has a beam, the 秤杆, and a weight that slides along it, the 秤砣. The saying 心里有杆秤 'to have a steelyard in one's heart' means to know very well what is fair; there 杆 is the measure word for 秤.