How do I convert centimeters to decimeters?
Divide by 10. A decimetre is 10 cm, so you move the decimal point one place to the left.
37 cm is 3.7 dm and 4.5 cm is 0.45 dm. A 30 cm school ruler is exactly 3 decimetres, if anyone ever asks.
When are decimeters commonly used?
Decimeters are rarely used for length, as people go from centimeters straight to meters. They do turn up in volume: a cube 1 decimeter on each side holds exactly one liter.
What is a centimeter?
A centimeter (cm) is one hundredth of a meter and just under four tenths of an inch (0.3937 inches). The prefix comes from the Latin centum, a hundred.
Divide centimeters by 30.48 to get feet, or multiply feet by 30.48 to get centimeters. The factor is exact, as a foot is 30.48cm, and a single centimeter is about 0.0328 feet.
The centimeter was the base unit of length in the CGS (centimeter, gram, second) system that physicists used before SI, which is why older physics talks about dynes and ergs.
What is a decimeter?
A decimeter (dm) is one tenth of a meter, or 10 centimeters. The 'deci' is the SI prefix for 10^-1.
The decimeter is rarely used by itself, since people go from centimeters straight to meters. You mostly meet it as the cubic decimeter, which is exactly one liter.
A decimeter is about 3.937 inches, so just under four. Divide inches by 3.937 – or multiply by 0.254 – to go the other way.