I have the number 0.5, I would like to turn it into the string 0.500.

Or more broadly, I have some function which returns a value ( in this case exactly 0.5), but I want to turn the number into a string and extend the "visible" accuracy to three decimal places.

For example,

Range("R8").FormulaR1C1 = "=ROUND(AVERAGE(R2C10:R" & last_row & "C10),3)" ' this is equal to 0.5
avg_life = Range("R8")
Range("R8") = avg_life & " " & avg_life
Now, Range("R8") displays "0.5 0.5" and not "0.500 0.500" which is what I want to display.