How can one pip = ten dollars w/ $100k lots if eur/usd exchange rate is 1.55821?

[John]

I would appreciate some help with my math here. EUR/USD exchange rate is 1.55821.  FIVE decimal places.  Most sites I see show only four when discussing the pip but FXCM's software shows five. .00001 * $100k = $1.  Yet FXCM's software states that one pip is $10.  Why is this?  Are they just ignoring the billionth place and using the millionth as the pip instead?

[Alex]

EURUSD is quoted to 4 decimal places by convention, so 1 pip is 0.0001 and that's $10 on a $100K lot. FXCM may quote to five decimal places, but that doesn't change the market convention.