Paul makes pencils, making 100 pencils a day five days a week. He started the week with 80 pencils in his stock, and during the week he sold 350 pencils. How many pencils did he have in his stock at the end of the week?
Making 100 pencils a day, he made 100 pencils/day * 5 days/week = <<100*5=500>>500 pencils during the week.
With the pencils from the stock, he got 500 pencils + 80 pencils = <<500+80=580>>580 pencils.
Subtracting the ones he sold, he has 580 pencils - 350 pencils = <<580-350=230>>230 pencils.
#### 230