How would you make up 100 ml of a 0.10 m nacl solution?

There are a number of ways to express concentration of a solution. This includes molarity. Molarity is expressed as the number of moles of solute per volume of the solution. Calculations are as follows:

0.10 M NaCl = 0.10 mol NaCl/ L solution
mol NaCl = 0.10 mol NaCl/ L solution (0.100 L solution) = 0.01 mol NaCl
Mass of NaCl = 0.01 mol NaCl (58.44 g NaCl / 1 mol NaCl) = 0.5844 g NaCl

In order to make 100 mL of 0.10 M NaCl solution, you need to dissolve 0.5844 g of NaCl salt in water.