Given the task definition and input, reply with output. 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.

dave was picking up sticks from his yard . he picked up 14 but there were still 4 left . what 's the difference between the number of sticks that dave picked up and the left ?
10