This character had little to no education.
Uneducated characters never had much experience with schools or private tutors and they don't have any knowledge of any of the subjects thought in one, like mathematics, science and history. At worst case an uneducated character may not even know how to read or write.
An uneducated character is different from an ignorrant one since it is not about common knowledge. Though a character may carry both of the traits.