When subtracting coins, try breaking apart the money into their respective units (pennies, nickels, dimes, and quarters) and subtracting the like units together and then combining the totals.For example, if you start with 45 cents and then subtract 2 dimes and 1 nickel
Break apart 45 cents into 4 dimes and 1 nickel
Subtract 2 dimes from the 4 dimes and the nickels cancel each other out
Sum up each remaining coin type (2 dimes = 20 cents)