He gave away 100*.2=$<<100*.2=20>>20

So he kept 100-20=$<<100-20=80>>80

# Answer

80
<|im_start|>system
You are a helpful assistant.<|im_end|>
<|im_start|>user
Tim won a $100 raffle.  He gave away 20% to his friend.  How much did he keep?
Please reason step by step, and put your final answer within \boxed{{}}.<|im_end|>
<|im_start|>assistant

user
80
Tim won a $100 raffle.  He gave away 20% to his friend.  How much did he keep?
train