Siri Intents & Shortcuts: How to get Siri to read numbers as individual digits?

In my Siri

intentdefinition
file, I have a declared a success response format along the lines of:

Here are the latest arrivals at

trainStationCode
.

trainStationCode
is a
String
comprising of digits only, e.g.
01354
,
61020
, etc.

When Siri reads the sentence it treats the

trainStationCode
as a number, e.g.

Here are the latest arrivals at sixty one thousand and twenty.

Is there a way to get Siri to read numbers as individual digits, i.e.

Here are the latest arrivals at six one zero two zero.