4 centimeters in decimeters

Conversion formula
How to convert 4 centimeters to decimeters?

We know (by definition) that: $1\mathrm{cm}=0.1\mathrm{dm}$

We can set up a proportion to solve for the number of decimeters.

Now, we cross multiply to solve for our unknown $x$:

Conclusion: 4 ⁢ cm = 0.4 ⁢ dm

Conversion in the opposite direction

The inverse of the conversion factor is that 1 decimeter is equal to 2.5 times 4 centimeters.

It can also be expressed as: 4 centimeters is equal to $\frac{1}{\mathrm{2.5}}$ decimeters.

Approximation

An approximate numerical result would be: four centimeters is about zero decimeters, or alternatively, a decimeter is about zero times four centimeters.