Zero

This is from my dad (Ellen's sleeping over there for a few days):

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Sitting at starbucks. I say to ellen,

"if we count we usually count starting with 1."

She: right.

me: then what is the point of zero?

she: how else can we understand 4 minus 4, or 10 minus 10.

I just nodded sagely, sipped my water and ate some more cookie.

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