Workflow calculated field strange result

In quote module I’ve create a custom field named CIPAG, type value, audit selected, inline editor selected. I want create a workflow operation that multiply the value subtotal with 0,05. In workflow action I selected calculated field and I wrote this formula: {multiply({P0};0,05)} where {P0} is subtotal.It works… but if I update the value of subtotal I obtain strange result.
For {P0} = 100,00 -> Value = 5,00
It’s ok, but…
For {P0} = 50,00 -> Value = 25,00 (instead of 2,5)
For {P0} = 150,00 -> Value = 75,00 (instead of 7,5)
For {P0} = 200,00 -> Value = 10,00 (It’s ok)
For {P0} = 215,00 -> Value = 1.075,00 (instead of 10,75)
ETC…

Anyone can help me?

Hi,
in my experience, such problems can be caused by mixing dots and commas within your values. Have you tried different combinations, also in regards to your user profile setting (there is a setting for the decimal character)?

The decimal character Is set top commas on my profile setting.