% This file is embedded in datatool-user.pdf version 3.0.1 2025-03-05
% Example 7 Datum Control Sequences to Floating Point Variables
% Label: "ex:datumfp"
% arara: pdflatex
% arara: pdfcrop
\documentclass[12pt]{article}
\pagestyle{empty}
\usepackage{datatool-base}
\usepackage{siunitx}
\DTLparse{\numA}{1,500.0}
\DTLsetfpdatum{\numB}{\num{1.5e-4}}{1.5e-4} 
\begin{document}
A = \numA \space (value: \DTLdatumvalue\numA).
B = \numB \space (value: \DTLdatumvalue\numB). 

\ExplSyntaxOn
\datatool_set_fp:Nn \l_tmpa_fp { \numA }
\datatool_set_fp:Nn \l_tmpb_fp { \numB }
\fp_to_tl:N \l_tmpa_fp \c_space_tl \texttimes \c_space_tl
\fp_to_tl:N \l_tmpb_fp \c_space_tl = \c_space_tl
\fp_eval:n { \l_tmpa_fp * \l_tmpb_fp }
\ExplSyntaxOff 
\end{document}