Given a math word problem, answer the following question. You might need to apply addition or subtraction mathematical operators on the numbers embedded in the text to answer the question and then only report the final numerical answer.

after buying a dress he went to a gardening store and bought his mom some ornamental plants . if the plants originally cost $ 467 and he was able to get a $ 399 discount how much did he actually spend on buying the plants ?
68

ellen has 6 more balls than marin . marin has 9 balls . how many balls does ellen have ?
15

mrs. hilt had 38 marbles . she lost 15 of them . how many marbles does she have left ?
23