Question 966987: please help me understand how i round a number/decimal.
(the parenthesis is the number of the place value i'm suppose to round)
example:
3(2),264.246
4.(2)26
33(9)7.2
Answer by KMST(5328)   (Show Source):
You can put this solution on YOUR website! When you round,
the digits to the right of the digit in parentheses are replaced by zeros
(or are not written, if that makes sense).
The digit in parentheses may stay the same or change
(often the change is to go up by one),
whichever makes the rounded number closest to the original number.
For example, if I am drawing a floor plan,
and I calculate that the width of a window in my drawing must be 4.249999 cm,
I would round it to 4.2 cm,
because 4.2 is between 4.2 and 4.3, but it is closer to 4.24999 than 4.3,
but if the calculated number was 4.25001, I would round to 4.3,
because 4.3 is closer to 4.25001 than 4.2.
If the un-rounded number is 4.25 (or 4.2500),
it is as close to 4.2 as it is to 4.3.
In a case like that, it is customary to round up (4.25 is rounded to 4.3).
The rounding "recipe" is to look at the digit right after the one you may be changing,
and if that next digit is 5 or more, you change the digit.
Otherwise, you keep it as it is.
4.(2)26 is rounded to  .
4.226 is between 4.2 and 4.3.
It is closer to 4.2, so the rounded answer is .
The rounding "recipe" says that the (2) digit in parentheses is not changed,
because the next digit is 2, which is not 5 or more.
3(2),264.246 is rounded to 
32,000<32,264.246<33,000
It is easy to see that 32,000 is closer to 32,264.246 than 33,000.
The rounding "recipe" says that the (2) digit in parentheses is not changed,
because the next digit to the right is 2, which is not 5 or more than 5.
33(9)7.2 is rounded to 
3397.2 is between 3390 and 3400.
Because the digit to the right of (9) is 7,
which is more than 5, we have to change the (9).
Adding 1 to the 9 digit gives you 10, which is not a digit,
but we "carry the 1", as if we were adding, and round to 3400.
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