That much sodium contains 0.761 moles.
To determine the number of moles you have in a certain mass, you need to use molar mass.
Molar mass tells you what the exact mass of 1 mole of a substance is. In your case, the molar mass of sodium is approximately 23.0 g/mol.
This means that 1 mole of sodium will weigh 23.0 g. Since you have less than that, you can expect to have less than one mole.