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.
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Question: A waiter had 9 tables he was waiting on , with 4 women and 3 men at each table . How many customers total did the waiter have ?

Answer: 63


Question: Ron weighed 2 colored metal balls during a science class . The blue ball weighed 6 pounds and the brown ball weighed 3.12 pounds . If Ron places both balls on the scale at the same time , what will the scale read ?

Answer: 9.12


Question: Kenji and his classmates placed colored blocks on a scale during a science lab . The yellow block weighed 0.6 pounds and the green block weighed 0.4 pounds . How much more did the yellow block weigh than the green block ?

Answer:
0.2