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Antidotia
Antidotia
Antidotia

Station  9
Antidots 

In our dots-and-boxes machines we’ve been working with dots, which we draw as solid dots.
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We now need the notion of the opposite of dot.

Like matter and antimatter, which annihilate when brought together, a dot and an antidot should also annihilate – POOF! – when brought together to leave nothing behind.
Let’s draw antidots as hollow circles.
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If a dot represents 11, then an antidot represents 1-1, and bringing one of each together leaves zero.

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Question 1

Annihilate the dot and the antidot by dragging them together!

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Even without a machine we can conduct basic arithmetic with dots and antidots.

Can you make sense of these pictures?

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By the way, some students prefer to call the opposite of a dot a tod. Can you guess what made them think of that name?

Antidotia
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