If you are unable to find the right math nodes you might need to install LE Extended Library which contains a lot of additional math nodes for blueprints. I don’t think it supports 4.19 yet only up to 4.18.x but I am sure it will be getting an update soon for the current engine version. I haven’t done much digging around in all this myself so you may not actually need it but from what I can tell it fills in a bunch of missing math stuff for blueprint use.