# Luis's Random Calculation

Luis has a simple calculator that has buttons for the digits 0 through 9, each of the 4 basic operations $$(+, - \times, \div)$$, and an '=' button. Luis pushes a digit followed by the '+' sign, followed by another digit, followed by the '-' sign, followed by another digit and then the '=' sign. How many different answers could Luis get?

Details and assumptions

The 3 digits pressed can be the same, e.g. $$1 + 1 - 2$$ is valid.

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