get yerself an Abacus....it makes maths simple....
....but having said that ..we over here have, to contend with two...different units of measurement...i.e. ..like your $ our currency is 100 parts of...a £....our fuel is in litres,...our weights are in kilo,s,....but...our speedo,s in our cars are still in MPH...and our road signs are in miles...it can be confusing....and just noticed today...that my new car,s speed is shown in mph and kms....both at the same time......