A pip is the last decimal place of a quotation. The Pip or POINT as it is sometimes referred to depending on context is how we will measure our profit or loss. For example if the EUR/USD moves from 0.9550 to 0.9551 that is one Pip.

As each currency has its own value it is necessary to calculate the value of a pip for that particular currency. We also want a constant so we will assume that we want to convert everything to US Dollars. In currencies where the US Dollar is quoted first the calculation would be as follows.

Example JPY rate of 116.73 (notice the JPY only goes to two decimal places, most of the other currencies have four decimal places)
In the case of the JPY 1 pip would be .01 therefore
USD/JPY: (.01 divided by exchange rate = pip value) so .01/116.73=0.0000856

USD/CHF: (.0001 divided by exchange rate = pip value) so .0001/1.4840 = 0.0000673

USD/CAD: (.0001 divided by exchange rate = pip value) so .0001/1.5223 = 0.0001522

In the case where the US Dollar is not quoted first and we want to get to the US Dollar value we have to add one more step.

EUR/USD: (0.0001 divided by exchange rate = pip value) so .0001/0.9887 = EUR 0.0001011 but we want to get back to US Dollars so we add another little calculation which is EUR X Exchange rate so 0.0001011 X 0.9887 = 0.0000999 when rounded up it would be 0.0001.
GBP/USD: (0.0001 divided by exchange rate = pip value) so 0.0001/1.5506 = GBP 0.0000644 but we want to get back to US Dollars so we add another little calculation which is GBP X Exchange rate so 0.0000644 X 1.5506 = 0.0000998 when rounded up it would be 0.0001.

I hope you get the idea.