Hello @mehsan, thank you for the question!
Looking at the screenshot, it looks like the number specified is 1..10. When I try adding the same value on my system, the error I see with this is "Error: The input must be numeric."
However, if I remove the extra ".", and enter just 1.10, then the error goes away, and the Watch block shows the number.
Do you see similar results when you change the number?
Note: For questions (or more resources) on Dynamo, I would suggest checking out: https://forum.dynamobim.com
Lance Coffey
Technical Support Specialist