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"What is 100" can depend on the context, but here are some possible explanations:

If it's a question:

What is 100? – It could refer to a number, percentage, monetary value, etc.

If it's a shortlist:

"CAD 100" might be intended, meaning 100 Canadian dollars (CAD = Canadian Dollar).

In a mathematical context:

It could be part of a question or problem: "What is 100 x 2?" etc.

Can you provide a bit more information about the context in which you are using "What is 100"? So that I can give a more precise answer.