Here you have one tenth of the original quantity of margarine.
if 100 grams of margarine has 0.70 grams of sodium, then one tenth of the margarine has one tenth of the sodium. So 10 grams of margarine has
0.070 grams of sodium chloride, keeping track of the significant figures.
If, for some reason, you need the number of moles present in 10 grams, it would be:
(#grams sodium chloride)/(#grams/mole of sodium chloride)
(0.070 grams)/(58.5 grams/mole) = 0.0012 moles of Sodium Chloride