Explain how to compare 513251 and 513521 to find the greater number

What you do is look at the numbers in order from the greatest number, to the least. For example, in this problem, we would start with the 5 in 513251, and the 5 in 513521. Since they are both fives, we don't know yet which one is bigger. So we move onto the next number, which would be the 1 in 513251, and the 1 in 513521. They are both the same, so we go onto the 3 in 513251, and the 3 in 513521. Those are also both the same, to we go onto the 2 in 513251, and the 5 in 513521. As you can see, the 5 from 513521 is greater then the 2 in 513251, so that shows that 513521 is greater.

The answer maybbe c