A 3-input precision adder is combined with a 3-output active precision multiple. The multiple input is normalized to the adder output, so you can have 4 adder outputs total.
Very low gain and offset error make this a perfect tool for adding and splitting pitch CVs, but it is also a great general purpose tool. Of course works for audio as well.
A RGB-LED shows the adder output signal (red positive, blue negative) and multiple input (green, positive only)
You can multiply an input by 2 or 3, by patching the multiple outputs to the adder inputs.