The Math Behind the NRIC

[carteki]

Some useless information that has come to light ... thanks to http://ayumilovemaple.wordpress.com/200 ... ification/

Regarding the NRIC math behind the letter, it’s called a checksum. This is to help check whether the actual IC numbers are valid and not just random numbers.

The math goes like this:

1) Take for example I want to test the NRIC number S1234567. The first digit you multiply by 2, second multiply by 7, third by 6, fourth by 5, fifth by 4, sixth by 3, seventh by 2. Then you add the totals together. So,1×2+2×7+3×6+4×5+5×4+6×3+7×2=106.

2) If the first letter of the NRIC starts with T or G, add 4 to the total.

3) Then you divide the number by 11 and get the remainder. 106/11=9r7

4) You can get the alphabet depending on the IC type (the first letter in the IC) using the code below:
If the IC starts with S or T: 0=J, 1=Z, 2=I, 3=H, 4=G, 5=F, 6=E, 7=D, 8=C, 9=B, 10=A
If the IC starts with F or G: 0=X, 1=W, 2=U, 3=T, 4=R, 5=Q, 6=P, 7=N, 8=M, 9=L, 10=K

[Strong Eagle]

Most account numbers, like your checking account numbers, are checksum verified.

Simplest is mod 10, double add double... that is, a weight of 1-2-1-2... but also can return false positives, ie, account number is not OK but still calculates the correct check digit.

The formula you have shown is mod 11, weight 1-3-5-7 and very commonly used. Much better at catching errors, but unless you are using letters like NRIC, you have to reject some account numbers because the check digit turns out to be 10.

Checksums exist to reduce machine read errors... magnetic swipes, optical reads, RFID reads, etc... yes even product numbers have check digits.

[ecureilx]

Some useless information that has come to light ... thanks to http://ayumilovemaple.wordpress.com/200 ... ification/

Regarding the NRIC math behind the letter, it’s called a checksum. This is to help check whether the actual IC numbers are valid and not just random numbers.

The math goes like this:

1) Take for example I want to test the NRIC number S1234567. The first digit you multiply by 2, second multiply by 7, third by 6, fourth by 5, fifth by 4, sixth by 3, seventh by 2. Then you add the totals together. So,1×2+2×7+3×6+4×5+5×4+6×3+7×2=106.

2) If the first letter of the NRIC starts with T or G, add 4 to the total.

3) Then you divide the number by 11 and get the remainder. 106/11=9r7

4) You can get the alphabet depending on the IC type (the first letter in the IC) using the code below:
If the IC starts with S or T: 0=J, 1=Z, 2=I, 3=H, 4=G, 5=F, 6=E, 7=D, 8=C, 9=B, 10=A
If the IC starts with F or G: 0=X, 1=W, 2=U, 3=T, 4=R, 5=Q, 6=P, 7=N, 8=M, 9=L, 10=K

now .. I was never strong in my maths .. my total comes to 132, and it is S, so what is the last letter again ??

[Tigerslayer]

Thats really interesting, I didnt realise there was a maths behind it.

now .. I was never strong in my maths .. my total comes to 132, and it is S, so what is the last letter again ??

Maths is not my strength either but 132 / 11 is 12 with 0 remainder therefore your last letter should be J, Correct?

[ecureilx]

Thats really interesting, I didnt realise there was a maths behind it.

now .. I was never strong in my maths .. my total comes to 132, and it is S, so what is the last letter again ??

Maths is not my strength either but 132 / 11 is 12 with 0 remainder therefore your last letter should be J, Correct?

Turns out, for my S IC, it is NOT J

[sundaymorningstaple]

Sounds about right to me. A squirrely NRIC for Squirrel. Doesn't make sense? I reckon it suits him to a "T".

[ecureilx]

Sounds about right to me. A squirrely NRIC for Squirrel. Doesn't make sense? I reckon it suits him to a "T".

and luckily you didn't issue it for me ..

atleast somebody noticed my 'talents' I guess ..

[Tigerslayer]

I have a few questions to clear this up...

- From which merchant did you purchase your NRIC?
- Where in Geylang did you buy it?
- and Do you still have the receipt?

[ecureilx]

I have a few questions to clear this up...

- From which merchant did you purchase your NRIC?
- Where in Geylang did you buy it?
- and Do you still have the receipt?

if you are questioning the IC issued by ICA, then there nothing I could say ...

No, I don't loiter around Geylang - punlike you ..

PS: I don't have a habit of buying ICs from merchants .. and I don't 'collect' IDs .. or ICs ..

[sundaymorningstaple]

Just names and people who know names.....

[ecureilx]

And how does the fact that Moi knows a bit more than am expected to know, and occasionally gets to shine, help solve the "MATH" problem here ?

And .. err ... as per HRH, does it mean I have a "FAKE" IC ? (as per the drift of 'knowing people' is implying ?? )

Yah, After all, it is not my turf .. so will wind my neck in ..

[Tigerslayer]

Joking aside the maths behind it seem pretty standard for all... If your NRIC isnt matching are you sure 132 is the correct outcome of all the multiplying and addition?

[ecureilx]

Joking aside the maths behind it seem pretty standard for all... If your NRIC isnt matching are you sure 132 is the correct outcome of all the multiplying and addition?

Yes .. or maybe I should try a different calculator ..

let me verify on another person's ic now and see how it goes !!!!