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.
--------
Question: In March it rained 0.81 inches . It rained 0.35 inches less in April than in March . How much did it rain in April ?

Answer: 0.46

Question: Sara had 100 pennies and 783 quarters in her bank . Her dad borrowed 271 quarters from Sara . How many quarters does she have now ?

Answer: 512

Question: Debby 's class is going on a field trip to the zoo . If each van can hold 4 people and there are 2 students and 6 adults going , how many vans will they need ?

Answer:
2