Rounding rules?

Question

Can anybody give me the rounding rules for addition and subtraction of whole numbers?It should be understandable by a fifth grader....any help would be much appreciated.

Answer 1

5 and above round up to tens, 50 above to hundreds, 500 to 1000 etc...

Answer 2

Under 5 you round down, over 5 you round up.

Answer 3

I'm afraid I don't quite understand the question. There are no rounding rules specific to addition or subtraction. There are just rules for rounding.

Examples of rounding to the nearest 10 (which means the answer has to be 10, 20, 30, 40, etc.):

36 rounded to the nearest 10--we ask ourselves, "Which is closer: 30 or 40?" The answer is 40.

125 rounded to the nearest 10--we ask ourselves, "Which is closer: 120 or 130?" Well, the rules state that the number following the target number forces us to round up if it's 5 or more, so the answer is 130.

Also, when beginning rounding, it can help to underline the number you have to decide if you are going to change or not and circle the number that is going to decide if it changes or not.

Some practice websites:

http://www.aaamath.com/est27a-rounding.h...

http://www.aplusmath.com/Flashcards/roun...

http://www.funbrain.com/tens/index.html

Answer 4

Anything higher than 0.5 should be rounded up; anything smaller than 0.5 should be rounded down.

Example 1:  8.4 is rounded to 8

Example 2:  4.7 is rounded to 5

OR, if you are given two or more numbers after the decimal, it is the same.

Example 1:  5.63 rounds to 5.6, which in turn is rounded to 6.

Example 2:  3.78 rounds to 3.8, which in turn is rounded to 4.

You look at the last number, and once again, if it is higher than 5 it rounds up; lower and it rounds down.  The second [and so on] number after the decimal determines if the numbers before it go up or if they stay the same.