"netsend: no method for 'float'".
Which Pd version are you using?
I ask because of a note in the [netsend] help patch: "lists work like 'send' (as of Pd 0.51)"
This means: If you are using Pd 0.51 or later, you should be able to send a number directly into [netsend] and it will be transmitted.
I confirm that this works in Pd 0.52.2:
Now, note that all the other examples in [netsend] help use "send" messages, such as "send foo $1" toward the bottom:
That "as of Pd 0.51" means: if you're using Pd 0.50.x or earlier, then the only way to make [netsend] work is with the "send" prefix:
But... if you're using an old Pd version... why? Probably better for you to upgrade.
(Also assuming here that you will later use [netsend] to send data to another process -- if it's all internal to Pd, then [send] / [receive] are better.)