Error in Python 3.6 and how to limit decimal places

[Raptor88]

Using Python 3.6 and tkinter that comes with it.

My tkinter code:

for myvalue in range(2,11):
    Radiobutton(rightFrame, text=myvalue*.1, font=(None, 14), variable=var, value=myvalue).pack()

Produces radio buttons with the following values:
o 0.2
o 0.30000000000000004
o 0.4
o 0.5
o 0.60000000000000001
o 0.70000000000000001
o 0.8
o 0.9
o 1.0

Why does Python 3.6 erroneously calculate the .3, .6 and .7 values?
And more importantly, what's the simplest way to limit the output to one decimal place using my code?