What data type should be used for a number that is 80 characters long?

Question

Pascal

What type of data should be used in a Pascal program so that it inserts a number of 80 characters long?

Answer 1

string or implement long arithmetic on arrays, the algorithm of arithmetic operations is like in the "column" school.

Answer 2

string
And then simply implement the operators as functions sum, multiply, divide, etc., which will perform the corresponding actions on long numbers as strings.
It's called "long arithmetic", google