Next on his checklist is wax to stick the feathers together. If the feathers require 42 g of wax and right now he has 8 g How many more grams of wax does he need?
1. What is the question asking? The question is asking how many more grams of wax does he need. 
2. What information do we have? We have that the feathers require 42 g of wax and right now he has 8 g. 
3. What do we need to find out? We need to find out how many more grams of wax he needs. 
4. How can we solve this problem? We can solve this problem by subtracting 8 g from 42 g. 

So, the answer is that he needs 34 g more of wax.