How many moles of sodium carbonate na2co3 are contained by 57.3 g of sodium carbonate

There are 0.54 moles of sodium carbonate are contained by  57.3 grams of sodium carbonate.

we can calculate number of moles in a compound by dividing number of grams of compound by the molar mass of the compound.
molar mass of sodium carbonate = 105.987 g/mol
now, 57.3 / 105.987 = 0.54 moles

Ithink its called the coefficent.