94. There is a balance scale, but all the weights are lost. However, there is 5 grams of yeast and 30 grams of ginger in the kitchen. Please use these two items to divide 500 grams of flour into two portions, one being 400 grams and the other 100 grams, using the balance scale only twice. Write a brief description of the process.
Reference answer: First, use 5 grams of yeast and 30 grams of ginger to weigh out 35 grams of flour, second, use the already weighed 35 grams of flour and 30 grams of ginger to weigh out 65 grams of flour, then put the 35 grams of flour and 65 grams of flour together to make 100 grams of flour, the remaining flour is 400 grams.