40 decimeters in centimeters

Conversion formula
How to convert 40 decimeters to centimeters?

We know (by definition) that: $1\mathrm{dm}=10\mathrm{cm}$

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

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

Conclusion: 40 ⁢ dm = 400 ⁢ cm

Conversion in the opposite direction

The inverse of the conversion factor is that 1 centimeter is equal to 0.0025 times 40 decimeters.

It can also be expressed as: 40 decimeters is equal to $\frac{1}{\mathrm{0.0025}}$ centimeters.

Approximation

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