It's not age, it's not score, it must be ranking. Dongdong is a primary school student with an estimated age of 6~ 14 years. Because 1067 is singular and cannot be divisible by 2, all the composite numbers of 6~ 14 are excluded, leaving 7,9, 1 1.
Dongdong came second with 97 points. His age is 1 1 year.