Question

If the digit to be dropped is less than 5, then the preceding digit is left unchanged.

Answer 1

Rounding off rules:
If the digit to be dropped is less than 5, keep the preceding digit unchanged.
Example: 7.82 rounded off to 7.8, 3.94 rounded off to 3.9.
If the digit to be dropped is more than 5, increase the preceding digit by one.
Example: 6.87 rounded off to 6.9, 12.78 rounded off to 12.8.
If the digit to be dropped is 5 followed by non-zero digits, increase the preceding digit by one.
Example: 16.351 rounded off to 16.4, 6.758 rounded off to 6.8.
If the digit to be dropped is 5 or 5 followed by zeros, and the preceding digit is even, keep it unchanged.
Example: 3.250 becomes 3.2, 12.650 becomes 12.6.
If the digit to be dropped is 5 or 5 followed by zeros, and the preceding digit is odd, increase it by one.
Example: 3.750 rounded off to 3.8, 16.150 rounded off to 16.2.