Thursday, August 30, 2018

Near-number arithmetic, part two: multiplication and division

The second of a three-part lesson on near-number arithmetic is now online, covering multiplication and division; next will come a video discussing and connecting all of the ☆-forms.  Key learning goals are:
  • how binary arithmetical operations operate on near-numbers (one pair of slices at a time, on all pairs of numbers, one from each slice);
  • familiarity with multiplication of basic near-numbers: finite × finite, finite × infinite, and infinite × infinite, and division via multiplying by the reciprocal;
  • ☆-forms for multiplication and division: 0+× +∞, +∞/+∞, and 0+/0+
  • The number zero times anything—including +∞—is simply zero.

Saturday, August 11, 2018

Near-number arithmetic, part one: addition and subtraction

The first of a three-part lesson on near-number arithmetic is now online!  This first video covers addition and subtraction; next will come a video on multiplication and division, and finally a video discussing and connecting all of the ☆-forms.  Key learning goals are:
  • how binary arithmetical operations operate on near-numbers (one pair of slices at a time, on all pairs of numbers, one from each slice);
  • familiarity with addition of basic near-numbers: finite + finite, finite + infinite, and infinite + infinite, and subtraction via adding the negative;
  • ☆-forms for addition and subtraction, including the fundamental ☆-form, +∞ + –∞.