ROUNDING RULES
1. Find the place to which you need to round. Circle the digit in the position
you wish to round .
2. Look at digit to the immediate right of the place you wish to round.
3. If the digit to the immediate right of the circled digit is 5 or bigger than 5
( i.e. 5,6,7,8,or 9) then the circled digit will increase by one. This is called
ROUNDING UP. If the digit to the immediate right is less than 5( i.e.
1,2,3 or 4) then the circled digit will stay the same. This is called
ROUNDING DOWN.
4. When rounding whole numbers, use zeros to fill in the place values of
all the digits to the right of the one being rounded.
5. When rounding decimals, drop all digits to the right of the place to be
rounded ( the circled digit). DO NOT ADD ZEROS IN THE EMPTY
SPOTS.
6. If the digit to be rounded is a 9 and it is followed by a 5 or bigger, then
when you round the 9 up to a 10, it means that your circled digit becomes
a 0 and you carry one to the digit next to the circled digit on its immediate
left.
7. When dealing with money, rounding to the nearest cent means rounding
to 2 places after the decimal. When rounding to the nearest dollar, you
don’t want any decimals in your answer.
.
8. When answers have been rounded, it is required that you use the symbol =
to let people know your answer is not exact.
EXAMPLES
a) If we are asked to round 236,145 to the nearest hundred, the digit we
wish to round is the 1. Circle it. When we look at the digit next to the 1,
on its immediate right, there is the digit 4. Since it is smaller than 5 the 1
stays the same. We will have to replace the last 2 digits (the 4 and the
5) with 2 zeros. Our answer becomes 236,100. This is called rounding
down.
b) If we are asked to round 102,983 to the nearest thousand, the digit we
wish to round is the 2. Circle it. When we look at the digit next to the 2,
on its immediate right, we see the digit 9. Since it is bigger than 5 the 9
will go up to 10. We replace the last 3 digits with 3 zeros. Our answer will
end up being 103, 000. This is called rounding down.
c) If we want to round 12.0354 to the nearest hundredth, we wish to round to
2 places after the decimal. Therefore, the digit we are rounding to is
the 3 in the decimal. Circle it. When we look at what comes after the
3, on its immediate right, we see that the digit is a 5. Therefore we will
have to round up. This means the 3 will go up to a 4. We drop all the
digits to the right of that digit so the answer becomes 12.04
d) If we are asked to round 23. 4069 to the nearest thousandth, we need to
round to 3 decimal places. Therefore the digit we are asked to round is
the 6. Circle it. When we look to the immediate right of the 6 there is
the digit 9. Since 9 is bigger than 5, the 6 will round up to a 7. Drop any
digits to the right of the digit to be rounded. The answer will be 23.407
e) Round $34.9624 to the nearest cent. The answer will be $34.96
f) Round $56,702.458 to the nearest cent. The answer will be $56,702.46
g) Round $56702.458 to the nearest dollar. The answer will be $56702
h) Round $369.835 to the nearest dollar. The answer will be $370