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1.
A term used to describe the giant complicated graphing calculators of yesteryear. They are often discontinued and are loaned out for you to use for the day by your public school math teachers.

This is a meme in reference to 2001: A Space Odyssey, comparing the calculator to that of HAL 9000, the giant supercomputer around which the series revolves. Hence, you have HAL + calculator equaling HALculator.
Mrs. D loaned Marc an enormous TI-82 out of her class set of +10 year-old calculators for use on the Algebra 2 final. "Mrs. D, what is this, A Space Odyssey?" said Marc. "How am I supposed to work this Halculator?"
by Marc P. June 02, 2006