08-28-2009, 08:26 PM
There are a number of checking systems for numbers, but none are perfect. I like the one where a final digit is added to make the number divisible by 7. The Canadian SIN has a check digit that involves multiplying the even digits by 2 and the odd digits by 1 and then ??? (I programmed it 25 years ago).
The common problems are:
Wrong digit
2 digits interchanged
2 digits interchanged around another digit -- abc becomes cab
whole number typed in one key over.
I had a problem where I was notified that a payment had been rejected for nsf and I knew that there was enough money. Turned out the company had mistyped the account number and was trying to take it from someone else's account. I don't know how long it would have taken if they'd had $200 in their account.
The common problems are:
Wrong digit
2 digits interchanged
2 digits interchanged around another digit -- abc becomes cab
whole number typed in one key over.
I had a problem where I was notified that a payment had been rejected for nsf and I knew that there was enough money. Turned out the company had mistyped the account number and was trying to take it from someone else's account. I don't know how long it would have taken if they'd had $200 in their account.
David
Moderato ma non troppo
Perth & Exeter Railway Company
Esquesing & Chinguacousy Radial Railway
In model railroading, there are between six and two hundred ways of performing a given task.
Most modellers can get two of them to work.
Moderato ma non troppo
Perth & Exeter Railway Company
Esquesing & Chinguacousy Radial Railway
In model railroading, there are between six and two hundred ways of performing a given task.
Most modellers can get two of them to work.