The Russian Rouble is the currency of Russia.
Rouble exchange rates (March 2019)
We suggest to use an ATM at the airport in Russia when you arrive as airport exchange rates are high. You can use the ATM at the hotel, in the city or at a bank as well.
Let your bank know that you will be traveling to Russia so that they do not block your cards while you are travelling (sometimes banks do this out of precaution). Bring more than one card if you have it. Carry your money and cards in a pocket that is not easily reached to prevent any pick-pocketing. It's smart to keep your cards and cash in separate pockets.
When estimating how much cash to bring for expenses such as meals and incidentals, a minimum of US$ 50 per day is a good estimation.
Here are some referential costs of daily expenses:
Cup of coffee: 2 $
Bottle of soda / water: 1 $
Sandwich: 4-5 $
Meal at a middle restaurant: 15$
Meal at a fast food restaurant: 7-10$
Check the program to see what is covered. All the meals and activities in the program are covered by the participation fee.