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.

Karin 's science class weighed plastic rings for an experiment . They found that the orange ring weighed 0.08333333333333333 ounce , the purple ring weighed 0.3333333333333333 ounce , and the white ring weighed 0.4166666666666667 ounce . What was the total weight of the plastic rings ?
0.8333333333333334

29 birds were sitting in a tree . Some more fly up to the tree . Then there were 42 birds in the tree . How many more flew up to the tree ?
13

The total number of students absent from B. Jones High School on a Monday after a significant snow fall was 218 . The total attendance that day was 1487 . How many students , in total , attend B. Jones High School ?

1705