664 metric teaspoons in US customary teaspoons

Conversion formula
How to convert 664 metric teaspoons to US customary teaspoons?

We know (by definition) that: $1\mathrm{brteaspoon}\approx 1.01442068105529\mathrm{usteaspoon}$

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

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

Conclusion: 664 ⁢ brteaspoon ≈ 673.5753322207125 ⁢ usteaspoon

Conversion in the opposite direction

The inverse of the conversion factor is that 1 US customary teaspoon is equal to 0.00148461493787651 times 664 metric teaspoons.

It can also be expressed as: 664 metric teaspoons is equal to $\frac{1}{\mathrm{0.00148461493787651}}$ US customary teaspoons.

Approximation

An approximate numerical result would be: six hundred and sixty-four metric teaspoons is about six hundred and seventy-three point five eight US customary teaspoons, or alternatively, a US customary teaspoon is about zero times six hundred and sixty-four metric teaspoons.