Calculating BigDecimal with Double Expression Syntax

[rayzorsan]

Hello,

I believe I am using incorrect syntax in the expression builder. I want to calculate a row that is big decimal with a row that is double.

Row 1 has a unit price which is a big decimal.

Row 2 has a conversion rate which is a double.

BigDecimal.valueOf(row1.UnitPrice.doubleValue() * row2.Conversion_Rate__c) 

Error Message is: 

Exception in thread "main" java.lang.Error: Unresolved compilation problem: 

Is there something else I need to check?

Thanks

[rayzorsan]

Okay this ended up in the wrong topic because of the autopopulation thing for subject. I cannot move it to where it should be.