639 US customary teaspoons in US customary cups

Conversion formula
How to convert 639 US customary teaspoons to US customary cups?

We know (by definition) that: $1\mathrm{usteaspoon}\approx 0.0208333333333333\mathrm{uscup}$

We can set up a proportion to solve for the number of US customary cups.

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

Conclusion: 639 ⁢ usteaspoon ≈ 13.312499999999979 ⁢ uscup

Conversion in the opposite direction

The inverse of the conversion factor is that 1 US customary cup is equal to 0.0751173708920188 times 639 US customary teaspoons.

It can also be expressed as: 639 US customary teaspoons is equal to $\frac{1}{\mathrm{0.0751173708920188}}$ US customary cups.

Approximation

An approximate numerical result would be: six hundred and thirty-nine US customary teaspoons is about thirteen point three one US customary cups, or alternatively, a US customary cup is about zero point zero eight times six hundred and thirty-nine US customary teaspoons.