Simplify the following text for a Grade 14 native English-speaking person.
Original: The National Polytechnic Institute ( Spanish : Instituto PolitÃ cnico Nacional , IPN ) is a public university located in Mexico City .
Simplified: The National Polytechnic Institute ( in Spanish : Instituto PolitÃ cnico Nacional , IPN , or simply as PolitÃ cnico ) is one of the largest public universities in Mexico .