Very roughly determine what the unit of currency (euros, kroner, Swiss francs, or whatever) is worth in American dollars. For example, let's say the exchange rate is €1 = $1.10. If a strudel costs €5, then it costs five times $1.10, or $5.50. Ten euros, at this rate, forex pairs
, would be about $11, and €250 = $275 (figure 250 plus about one-tenth more).