$ perl -MDevel::Peek -wle '$x=12345; print Dump $x; print "$x"; print Dump $x'
SV = IV(0x1004f958) at 0x1004f958
  REFCNT = 1
  FLAGS = (IOK,pIOK)
  IV = 12345

12345
SV = PVIV(0x10023810) at 0x1004f958
  REFCNT = 1
  FLAGS = (IOK,POK,pIOK,pPOK)
  IV = 12345
  PV = 0x10040c08 "12345"\0
  CUR = 5
  LEN = 8

##</code><code>##

$x="12345.67"; $y=$x+1;