Share 'Adjusting chocolate amount based on the percentage: Kitchen Confectionery'

I am reading the book, 'Cooking with Chocolate'.  One of the discussions concerns adjusting the quantity of chocolate  based on the percent of the chocolate being used if it differs from that called for in the recipe.  Example - recipe calls for 330 g of 70% chocolate OR 350 g of 60% chocolate, etc.There is no formula included to make the conversion dependent on the amount of chocolate called for…