641 ? 797
When we compare numbers with several digits and having an equal number of digits, they are compared from left to right, by comparing the first digit, if one of the digits is higher then that number is higher , if the digits are equal we continu with the following digit from left to right and we compare them.
If the numbers have unequal number of digits, then the number which has more digits is larger.
1 = 1
6 > 2
2 < 5
By learning math, you learn to think.