IELTS, TOEFL & TOEIC writing: When should I use brackets/parentheses?
The problem is with the student's use of brackets. When do we use brackets? Well, we use brackets when information is added to a sentence which is not vital, but is 'nice' to include. In other words, if we take the bracketed information out of the sentence, it's still completely understandable and correct.
In the sentence above, if we took the bracketed information away, we'd be in trouble because the sentence wouldn't make sense. Consider this example:
Note that if we took away 'from 10% to 25%' in the above sentence, it would still make sense but the extra, bracketed information provides even more clarity and helps the reader to understand what 'grew significantly' actually means (growth from 10% to 25%).