Palindrome number is easy if you see the trick, not easy if you don't see the trick. (also assumes get first digit and get last digit of number is obvious)
Imho, this is like adding the digits from 1 to 100 by hand. Easy if you see the trick, not easy if you don't see the trick.
Is being able to "see the trick" easy? How do you teach or learn "seeing the trick"
https://leetcode.com/problems/palindrome-number/description/