Error: Data conversion failed from variant to number

Hello very helpful community,

This time i cannot easily reproduce my code. essentially i want to introduce a number inserted as input in a cluster to python and i get this error. Not sure how to go round it. I am attaching the problem in case you can help me solve it. I am confused as outside the cluster both variables are considered floating points introduced by a slider but somehow they are not recognised as such in the cluster.

best,
ioanna