420 decimeters in kilometers

Conversion formula
How to convert 420 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: 420 ⁢ dm = 0.042 ⁢ km

Conversion in the opposite direction

The inverse of the conversion factor is that 1 kilometer is equal to 23.8095238095238 times 420 decimeters.

It can also be expressed as: 420 decimeters is equal to $\frac{1}{\mathrm{23.8095238095238}}$ kilometers.

Approximation

An approximate numerical result would be: four hundred and twenty decimeters is about zero point zero four kilometers, or alternatively, a kilometer is about twenty-three point eight zero times four hundred and twenty decimeters.