Baker:
Bakers use addding and subtracting fraction when they are going to need less of somethong or more of something.They might also need it when they are going to bake something.This math term is useful for them.
Cheffs:
A cheff might use addding and subtracting fractions sometimes while needing to cook something really important or when he needs to use it at good times.Also, when he needs to know how much too put in different kinds of ingredients to his or her food.