File: Data.xml <?xml version="1.0"?> <numbers> <x>4</x> <y>3.2</y> <z>11</z> </numbers> File: Transform.xslt <?xml version="1.0"?> <xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="1.0"> <xsl:output method="xml" omit-xml-declaration="yes" /> <xsl:template match="numbers"> 3.2 + string-length("3.2") = <xsl:value-of select="y + string-length(y)" /> </xsl:template> </xsl:stylesheet> Output: 3.2 + string-length("3.2") = 6.2