Does 0.5 round up or down?

User Avatar

Wiki User

โˆ™ 2010-10-07 18:22:19

Best Answer


Round up or down so that the new last digit is even.


Some people advise you to round up 0.5 others say round down. The problem with that approach is as follows:

In the first case

If the number is 0.0 you don't need to round

If the number is 0.1, 0.2, 0.3 or 0.4 you round down

If the number is 0.5, 0.6, 0.7, 0.8 or 0.9 you round up

So 4 downs and 5 ups (and one no change).

Net Result: you introduce an upward bias.

In the second scenario, you introduce a downward bias through rounding.

Possible solution:

Round up from 0.5 half the time, round down the other half. That satisfies the bias problem but introduces another - that of reproducibility. If someone else were to look at your data would they round up/down the same way you did? Unlikely. You need a system which will round 0.5 up half the time and down half the time but where the decision is made for you.

Hence the best solution is the answer given above: Round up or down so that the new last digit is even.

Long and a bit roundabout but it should satisfy not only the mathematicians but the statisticians and pedants as well.

User Avatar

Wiki User

โˆ™ 2010-10-07 18:22:19
This answer is:
User Avatar
Study guides


20 cards

A polynomial of degree zero is a constant term

The grouping method of factoring can still be used when only some of the terms share a common factor A True B False

The sum or difference of p and q is the of the x-term in the trinomial

A number a power of a variable or a product of the two is a monomial while a polynomial is the of monomials

See all cards
1449 Reviews
More answers
User Avatar


Lvl 1
โˆ™ 2020-06-24 10:08:45


This answer is:
User Avatar

Add your answer:

Earn +20 pts
Q: Does 0.5 round up or down?
Write your answer...
Still have questions?
magnify glass
People also asked

What is the fraction of 64?

View results

What is 87.5 percent of 1 meter in centimeters?

View results

How do i simlify the fraction 22 4?

View results