Hex() treats some numbers differently?

[TeddyTech]

I was trying to write a routine that moved through a decimal range and gave me the difference in hex. 

The difference would be correct in decimal, but when I tried to convert it to hex it always returned zero.

After struggling with this for a while thinking I was doing something wrong I finally broke out the code I was struggling with and built this small test.  It does not behave like I expect. 

Is this a bug or is it working-as-designed and I just don't understand some nuance of "string" numeric vs. "real" numeric?

Teddy 

$range = "2010-2023"

$rl = StringLeft($range, 4)

$rr = StringRight($range, 4)

ConsoleWrite("Diff (without hex())      =" & ($rr - $rl) & @CRLF)                       ;Diff (without hex())      =13

ConsoleWrite("Hex without Number()      =" & Hex($rr - $rl, 2) & @CRLF)                 ;Hex without Number()      =00

ConsoleWrite("Hex with Number() on sum  =" & Hex(Number($rr - $rl), 2) & @CRLF)         ;Hex with Number() on sum  =00 <-- this one is really confusing

ConsoleWrite("Hex with Number() on each =" & Hex(Number($rr) - Number($rl), 2) & @CRLF) ;Hex with Number() on each =0D

[jchd]

$range = "2010-2023"
$rl = StringLeft($range, 4)
$rr = StringRight($range, 4)
ConsoleWrite(VarGetType($rr - $rl) & @CRLF)

Because $rr - $rl isn't what you think it is.

[TeddyTech]

Thanks ... the VarGetType really helped make more sense out of this behavior. 

I've changed that original to $rl = Int(StringLeft($range,4)) and all is well.