When you take everything diagonally you're getting it 13. So why is it 13? Does anyone know reason for this? Even I too don't know, but we have a reason for it. So if you know, please do reply and you know, see nine plus four is also 13. Eight. List 513. And again six list seven is 13. So everything is the sum. Two numbers are the sum of 13. So why is that?