after allegations that some school fudged the numbers in the past. our don lemon looks into schools allegedly cheat for their students. >> reporter: michael mard den is worried. were you the only parent concerned? >> no, by all means. >> reporter: someone may have changed the answer on the standardized tests on his daughter's school last year. do you have concern? >> of course i have concern like any other parent. i have concern. i hope that there's no cheetding. and if it is cheating, there needs to be a punishment for it. >> reporter: and he's not alone. the state of georgia is investigating 10% of its elementary and middle schools, 191 of them, because of moderate to severe concern over test results in 2009. when the answer sheets like these were scored, the computer scanners could tell when the bubbles were erased and the answers changed. kathleen mathers heads the state audit. >> it's not just someone had changed a bunch of answers it's that when they changed answers