Question 851207
Pizza is easier to picture.  If you have 100 slices of pizza and you are giving out 11 shares (8 shares + 3 additional shares to the teenagers), you have 100/11 or 9.09 pieces per share.
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5 people will get 1 share of 9.09
3 people will get 2 shares of 18.18
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If you need whole numbers,
5 people will get 1 share of 9 each
3 people will get 2 shares of 18 each
4 pieces will be left over
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Same for paper, but you can't eat those ;-)