When we ask the kids to round a number it is because the questions does not require an exact answer. The picture below shows the steps that we ask the students to follow when rounding.
" There are 26 kids in the library and
41 kids in the cafeteria. About how many
kids are in the library and the cafeteria?"
Questions like this help the students get use to seeing the word "about" and understand that this is an estimation (or rounding) problem. Hope this has helped. Once again, please let me know if this was helpful... confusing... too much.. I'm doing all of this for you guys so feedback is always welcome. Thanks!!