According to Baidu Education, 3 10 mm is equal to 3 1 cm. Because 1 cm is equal to 10 mm, according to the conversion relationship, 3 10 is equal to 3 10 divided by 10, that is, 3 1 cm.

Millimeter, also known as millimeter (or millimeter), is the unit of length and rainfall, abbreviated as mm in English. 10 mm is equivalent to 1 cm, 100 mm is equivalent to 1 decimeter, and 1000 mm is equivalent to 1 meter (which means milli).