WPF Numeric Textbox control with a calculator?

I've always liked the ability to do simple calculations in the same place I'm entering a number when working in MS Money.

I know that DevExpress is working on one, but don't want to buy the full 开发者_开发知识库WPF bloat only for this control.

Do you know a control like that for WPF?

See CalculatorUpDown control from Extended WPF Toolkit project.