where is Divide - frame echo feature

Trying to emulate a Nuke workflow for green screen keying.
There is a screen correction workflow that requires a divide operation. What would be the math operation in Fusion that produces the screen correction plate?
Secondly - clean plate creation by adding up frames over the entire length of the clip. Is there something like a motion echo feature?

Thank you.

(Maybe I should just swallow hard and switch to Nuke - no?)

Not being familiar enough with Nuke (haven't used it in more than a decade), could you be more specific? There's a divide mode in the ChannelBooleans tool if all you need is the operation itself.

As for the second, I think what you need is the Trails tool.

thanks Bryan,
The Boolean Divide should do the trick, I overlooked that.
And I re-discovered Reactor and Echo tool is exactly what I need for making a clean plate.