The currency of Thailand is the Baht which consists of 100 Satangs. Coins include 25 satang, 50 satang, 1 Baht, 5 Baht and 10 Baht pieces but the confusing fact about coins is that they are of different sizes for the same value coin and only the newer coins have Arabic numerals.
The 5 Baht coin (silver with copper edge) and the 1 Baht coin (silver) each come in three sizes. The 10 Baht coin has a copper center with silver border, the 50 and 25 satang coins are copper colored, and both circulate in two sizes.
Paper money is clearer since the notes have Arabic (as well as Thai) numerals and are color coded as well as of different sizes for different denominations - the larger the denomination the larger the size. 10's are brown, 20's green, 50's blue, 100's red, 500's purple and 1000 Baht notes are grey.