instruction:
You are given a math word problem and you are supposed to apply a single mathematical operator like addition, subtraction, multiplication, or division on the numbers embedded in the text to answer the following question and then only report the final numerical answer.
question:
18 children were riding on the bus . at the bus stop some more children got on the bus . then there were 25 children altogether on the bus . how many children got on the bus at the bus stop ?
answer:
7

question:
robin 's hair was 15 inches long . if she cut off 5 inches how long is her hair now ?
answer:
10

question:
zach scored 42 points in the football game . ben scored 21 points . how many more points did zach score ?
answer:
21