What is the rule of rounding figure?

Answer 1

When rounding to a specific place, take a look at the digit immediately to the right of the target. If that digit is 4 or less, zero everything to the right of the target out. If that digit is 5 through 9, increase the target by one and zero everything to the right of it out. If the target is a 9, increasing it will turn it to zero and increase the digit to the left of the target by one.

Answer 2

The steps for bias-free rounding are as followsStep 1: establish where the number is to be rounded: this could be described in terms of significant figures or decimal places.

Step 2: look at the digits immediately after the one to which the number is to be rounded.

• if the next digit (or the number formed from the next digit onward) is smaller than 5 then simply get rid of all those digit;
• if the next digit (or the number formed from the next digit onward) is larger than 5 then increase the last digit of the rounded number by one and also get rid of all the digits after it.
  
• if the next digit is 5 than round the last digit to an even number.

Although many schools teach you to always round 5 up. However, doing so is inappropriate because it introduces an upward bias. The IEEE (Institute of Electronic and Electrical Engineers) standard 754 is to round 5 up or down so that the new last digit is even. See link for more: //en.wikipedia.org/wiki/Rounding#Round_half_to_even