Trip Advisor: "things to do."
Arrive in Prague and immediately go to the HSBC ATM to get your local currency called korunas. They are more abundant and hence cheaper to purchase WITHIN the Czech republic. You might think it's a hassle to walk over there, but you will significantly save money by using your own bank. Be accurate in guessing how much money you will need for your transactions and expenses. Don't hit the ATM more than twice.
Here is the HSBC bank branch for your ATM: Na Florenci 2116/15, Nové Město, 110 00 Praha 1, Map and address
Advice about other money exchanges in Prague (but will waste you money by adding fees.) You might find that you can pay Euros for goods locally, but the seller will be taking advantage of you and not be giving a good rate of exchange and "rounding up" is a scam.
Czech money is called a "koruna." (Like a "crown.") Roughly converted, 1 koruna is like 4.5 cents. 1 US dollar buys you about 22.7 korunas. Converter
100 Koruna = $4.41 (cup of coffee? a big Mac?)
600 Koruna = $26 (meal for two?)
2000 Koruna = $88 (train ticket?)
Best practice:
For Mom's use: HSBC in Arlington