Baker made 43 cakes. He sold some of them. If he still has 3 cakes left How many cakes did baker sell?
1. We know that the baker started with 43 cakes. 
2. We know that he sold some of them, which means that he now has less than 43 cakes. 
3. We know that he has 3 cakes left, which means that he sold 40 cakes.