You are given a math word problem and you are supposed to apply addition or subtraction mathematical operators on the numbers embedded in the text to answer the following question and then only report the final numerical answer.

In 1 week , Mitch 's family drank 0.5 carton of regular milk and 0.1 carton of soy milk . How much milk did they drink in all ?
0.6

Robin 's class is going on a field trip to the zoo . If each van can hold 8 people and there are 22 students and 2 adults going , how many vans will they need ?
3

A carpenter bought a piece of wood that was 8.9 centimeters long . Then he sawed 2.3 centimeters off the end . How long is the piece of wood now ?

6.6