Accuracy

• Computer numbers have limited size => limited precision.

• Rounding Errors

• Is (x+y)+z = x + (y+z)?

• Rounding with Guard, Round bits

  • Example: 2.56 x 100 + 2.34 x 102, using 3 significant digits
  • Result: 2.3656 x 100
  • Round: 2.37 x 100
  • Without guard bits, result: 2.36 x 100
  • Error of 1 Unit in the Last Place

• Why 2 bits?

  • Product could have leading 0, so shift left when normalizing

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