Which abbreviation is used for 1 decigram?

• A. 1 cg
• B. 1 dg
• C. 1 mg
• D. 1 g

Answer: (B)

Thinking in metric prefixes, deci- means one-tenth of the base unit. For mass, the base unit is the gram, so combining deci- with gram gives decigram, abbreviated as dg. That’s why 1 decigram is written as dg, since it represents one-tenth of a gram (0.1 g). For comparison, a centigram (cg) is one hundredth of a gram (0.01 g), a milligram (mg) is one thousandth of a gram (0.001 g), and a gram (g) is the base unit itself. If you convert, 1 dg = 0.1 g, and that helps see why the abbreviation dg is the correct one for 1 decigram.