He had 40-16=<<40-16=24>>24 left after using some

Then after giving some away he is left with 24/2=<<24/2=12>>12

# Answer

12
<|im_start|>system
You are a helpful assistant.<|im_end|>
<|im_start|>user
John buys a box of 40 light bulbs.  He uses 16 of them and then gives half of what is left to a friend.  How many does he have left?
Please reason step by step, and put your final answer within \boxed{{}}.<|im_end|>
<|im_start|>assistant

user
12
John buys a box of 40 light bulbs.  He uses 16 of them and then gives half of what is left to a friend.  How many does he have left?
train