How to remove a number in pascal?

Question

Informatics

Given a five digit number. What is the number you get if you remove the penultimate digit?
For example 15978 -> 1598.
Many thanks in advance!

Answer 1

r := (n div 100) * 10 + (n mod 10)

Answer 2

Convert the number to a string, collect a new string from the elements of the old one. Convert string back to number. For example it is possible so. Or find the first three digits (through division) and the last (through the remainder of the division). Then through addition and multiplication you get the result.