Tim mixed 0.9 grams of salt into a pot of soup he was cooking. Before he served the soup, Tim added 0.1 grams of salt. How much salt did Tim put into the soup in all?

Answer 1

Tim put 0.9 grams + 0.1 grams = <<0.9+0.1=1>>1 gram of salt into the soup. Answer: \boxed{1}.