i don't get this?

Question

Iodine is an essential nutrient in the human diet because it prevents goiter - a swelling of the thyroid gland. To obtain enough iodine, you can use iodized salt, which is 0.01% Nal by mass. How many kilograms of Nal should be added to 1000 kg of table salt to achieve this percentage of Nal?

Answer 1

% by mass NaI= 0.01%
% by mass NaI= 100%(mass of NaI / total mass of NaCl)



0.01%= 100% (X Kg NaI / 1000 Kg NaCl)

0.01% / 100 % = X Kg NaI / 1000Kg NaCl

0.0001 (1000 Kg NaCl) = X Kg NaI

X = 0.1 Kg NaI

Answer 2

1% would be 10kg.
0.01 percent would be 0.1kg or 100 grams.
It really does not require much, does it?