What is 25.65 rounded to one decimal place?

Answer 1

It is 25.6

Most schools teach you to always round 5 up (so the answer would be 25.7) but, while this is a simple rule to teach, it is not really correct. Under this rule:

• if the following digit is 0 you don't round;

• if the following digit is 1, 2, 3 or 4 you round down; and

• if the following digit is 5, 6, 7, 8 or 9 you round up.

As a result you are more likely to round up than round down and that introduces an upward bias into your calculations.

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