Why do we use 3 digits in county numbering?

By MUNGAI KIHANYA

The Sunday Nation

Nairobi,

09 May 2021

When recording measurements, the number of digits indicated is important because it shows the level of accuracy of the measuring equipment. For example, the regular ruler is subdivided into centimetres and millimetres. So, if it is used to measure, say the length of a pencil, the result may be written as 13.5cm.

Writing it this way tells the reader that the pencil’s tip was at the 13.5cm mark and there is no further subdivision on the ruler. What if it was 13cm?

In that case, it becomes necessary to write 13.0cm to indicate that the ruler has subdivisions that are smaller than centimetres. The ‘.0’ tells the reader that there are millimetres on the ruler.

When counting things, it is sometimes necessary to add zeroes in front of the digits in order to give the reader an indication of the largest number allowed. The Kenyan vehicle registration plates provide a good illustration.

Long ago, they had three letters and anywhere between one and three digits. Thus, one could have been KFG 4 and another KFG 45 and yet another, KFG 453.

Then the authorities realised that this kind of numbering was making life too easy for crooks and criminals. If a thief wanted to change the KFG 453 to a KFG 4, all he needed to do was paint over the ‘53’ with the background colour and no one would be any the wiser!

To make things more difficult, the registration plates were change to three letters and three digits. Zeroes were added in front of numbers less that 100; thus, KFG 4 now became KFG 004 and KFG 45 became KFG 045. Of course, KFG 453 remained unchanged.

Now it is a little more difficult to make the change from KFG 453 to KFG 004. The thief has to write the ‘00’ in front of the 4 and there is no space! Even a change to KFG 003 isn’t as easy a before.

The reason for picking three digits was that the number runs up to 999. If it had been to 9999, then KFG 4 would have been changed to KFG 0004 and KFG 453 to KFG 0453.

So now; if we were to assign numbers to 47 things, would there be a reason to use a three-digit system from 001 to 047? I can’t think of any.

Then why do we do that with the counties? Why is Mombasa numbered as ‘001’ and Nairobi ‘047’ instead of ‘01’ and ‘47’ respectively? Did we just copy the vehicle registration number system blindly?