How to set the box with different height?

Question

There are two boxes draw with multi-part nodes of TiKZ.

How to draw the lower box with more height? (the lower box should be with more vertical space)

\documentclass[border=10pt]{standalone}
\usepackage{tikz, tkz-graph}
\usetikzlibrary{arrows,arrows.meta,shapes,positioning,automata}
\usetikzlibrary{matrix,chains}
\thispagestyle{empty}
\usepackage{xcolor}
\definecolor{colorBall}{RGB}{51, 153, 204}
\definecolor{colorCircle}{RGB}{0, 255, 0}

\tikzset{
    multirectangle/.style={
        minimum width=20mm,
        minimum height=18mm,
        inner ysep=3mm,
        anchor=center,
        draw,
        fill=orange!20!white
    }
}
\begin{document}
\begin{tikzpicture}
\node (A) [rectangle split, rectangle split parts=2, multirectangle]{
    \textbf{float}
    \nodepart{two}
    $123.5$
};
\end{tikzpicture}
\end{document}

Answer 1

Unfortunately to multipart nodes is not possible to define different heights, so you need add some strut to part's content. For example:

\documentclass[margin=10pt]{standalone}
\usepackage{tikz, tkz-graph}

\usetikzlibrary{arrows.meta,automata,
                chains, matrix,
                positioning,
                shapes.multipart}   % <---
\newlength{\nph}                    % node part height

\begin{document}
\begin{tikzpicture}[
mpnv/.style = {draw,
    rectangle split,
    rectangle split parts=2,
               }
                    ]
\setlength{\nph}{22mm}                          % define node part height
\pgfmathsetlengthmacro{\npd}{0.48\nph}          % calculating node part baseline
\newcommand\mystrut{\rule[-\npd]{0pt}{\nph}}    % define new strut

\node (a) [mpnv] {
    \nodepart{one} \textbf{float}
    \nodepart{two} $123.5$ \mystrut %  <----------
                };
\end{tikzpicture}
\end{document}