Questions: How to define constants without units? Why scalar-error? What term is missing?

Hi,

I`m new to Mathcad and struggle with a few things.

1) I try to define a few values, like:

• Rm:=810MPa (that worked)
• Rz:=6,3 (without a unit)
• 

   

Mathcad always wants to have a unit. Can I somehow set a value without?

2) When I try to calculate, I get the error "this value must be a scalar or a matrix". I just want it to be a number. What`s wrong?

3) What does Mathcad require here?

Thanks!

Best regards
Martin