4 decimeters in kilometers

Conversion formula
How to convert 4 decimeters to kilometers?

We know (by definition) that: $1\mathrm{dm}=0.0001\mathrm{km}$

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

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

Conclusion: 4 ⁢ dm = 0.0004 ⁢ km

Conversion in the opposite direction

The inverse of the conversion factor is that 1 kilometer is equal to 2500 times 4 decimeters.

It can also be expressed as: 4 decimeters is equal to $\frac{1}{\mathrm{2500}}$ kilometers.

Approximation

An approximate numerical result would be: four decimeters is about zero kilometers, or alternatively, a kilometer is about two thousand, five hundred times four decimeters.