Cannot Multiply This NumberValue?

I tried to multiply this numbervalue.Value saying:

Monz.Value = Monz.Value * b

b in this case is the number value. However in the output it doesnt work and gives me an error saying:

attempt to perform arithmetic on local 'b' (a userdata value)

No idea what to do...?

Try

print(b)

to confirm your belief that it is a number.