What are the greatest and least 6-digit numbers in which the digit in the thousands place is twice the digit in the tens place?

Oh, what a happy little question! The greatest 6-digit number where the digit in the thousands place is twice the digit in the tens place is 986,432. And the smallest 6-digit number following the same rule is 164,823. Isn't it wonderful how numbers can dance together in such a harmonious way?