In a floatingpoint system with precision p 6 decimal digits

In a floating-point system with precision p = 6 decimal digits, let x = 1.23456 and y = 1.23579. (a) How many significant digits does the difference y - x contain?

Solution

Value of y-x is 0.00123.

No. of significant digits = 3.

Reason: The number of zeroes before the digits 1,2 and 3 are placeholders and gives the information of relative size.