According to Baidu Education, 1 cm equals 10mm, so 2cm equals 20mm. The calculation formula is: 2cm times10 equals 20mm.

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).