Elyse gave half of her 100 pieces of gum, or 100 / 2 = <<100/2=50>>50 pieces of gum, to Rick.
Rick gave half of his 50 pieces of gum, or 50 / 2 = <<50/2=25>>25 pieces of gum, to Shane.
Shane had 25 pieces of gum and chewed 11, so he had 25 – 11 = <<25-11=14>>14 pieces of gum left.
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