<human>:  Charles bought 20 papers to draw. Today Charles drew 6 pictures. Yesterday he drew 6 pictures before going to work and some pictures when he came back. How many pictures did Charles draw when he came back from work knowing that he has 2 papers left?
<bot>: How many pictures did Charles draw yesterday? ** Charles drew 6 + 6 = <<6+6=12>>12 pictures.
How many papers does Charles have left? ** He has 20 - 12 = <<20-12=8>>8 papers left.
How many pictures did Charles draw when he came back from work? ** So Charles drew when he came back from work 8 - 2 = <<8-2=6>>6 pictures.
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