639 centiliters in deciliters
Result
The conversion result is: 639 centiliters is equivalent to 63.9 deciliters.[1]
Conversion formula
How to convert 639 centiliters to deciliters?
We know (by definition) that: 1 centiliter ≈ 0.1 dl.
We can set up a proportion to solve for the number of deciliters.
1 centiliter / 639 centiliter ≈ 0.1 dl / x dl
Now, we cross multiply to solve for our unknown x:
x dl ≈ (639 centiliter / 1 centiliter) * 0.1 dl → x dl ≈ 63.900000000000006 dl
Conclusion:
639 centiliter ≈ 63.900000000000006 dl

Conversion in the opposite direction
The inverse of the conversion factor is that 1 deciliter is equal to 0.0156494522691706 times 639 centiliters.
It can also be expressed as: 639 centiliters is equal to 1 / 0.0156494522691706 deciliters.
Approximation
An approximate numerical result would be: six hundred and thirty-nine centiliters is about zero deciliters, or alternatively, a deciliter is about zero point zero two times six hundred and thirty-nine centiliters.
Footnotes
[1] The precision is 15 significant digits (fourteen digits to the right of the decimal point).
Results may contain small errors due to the use of floating point arithmetic.