Visit the website of the Central Bank of the Russian Federation or the National Bank of Ukraine. In the left column, find links to "currency rates"/ "Oftiny course grown to inozemnih currencies".
Refer to the table of exchange rates of the hryvnia to the ruble on the date of your stay. Or follow the link in the "Database currency" - http://www.cbr.ru/currency_base/D_print.aspx?date_req=17.02.2011 substituting the desired date is the last 8 digits in the address.
Turn the hryvnia into rubles on the basis of the hryvnia.
Use the "Currency calculator" as an alternative way of converting USD (and other currencies) - http://www.calc.ru/valut_calc.php. From the drop-down list, select the currency and enter their number. Click "Translate". This on-line calculator uses the exchange rates of the Central Bank of the Russian Federation.