I don’t know your context, but I think in this case it is not bad to add a “technical” integer attribute to your entity like _MaterialNumber. The value of this attribute is your material number parsed to an integer (use the function parseInteger).
Consider to use an event like an OnChange to set the _MaterialNumber attribute value correctly. So you have no need to do this for each display (better performance). In your view you can use _MaterialNumber to show without leading zeros. And you still have the original attribute available.
You can use the replaceAll function to strip leading zeros. This function accepts regular expressions. So, you can tell it to remove leading zeros with something like this:
replaceAll(MaterialNumber, '^0+', '')
If this is always true you could have a quick solution by parsing it to Integer, removing the leading zero’s and then back to String or Decimal*
For some documentation on the matter see:
parseInteger → https://docs.mendix.com/refguide/parse-integer
toString → https://docs.mendix.com/refguide7/to-string