type of zero in article [duplicate]

Question

How can I write a zero? I want this zero that have two bar inside its. Can I help me?

Answer 1

The zero of your screenshot.

\documentclass[a4paper,12pt]{article}
\usepackage{amsmath,amssymb}
\usepackage[bb=boondox]{mathalfa}

\begin{document}
$\mathbb{0}$
\end{document}

Answer 2

An alternative to overriding \mathbb with the boondox font that would also change the shape of blackboard bold capitals, might be using the STIX fonts (importing only the required glyph).

From the documentation of stix2 we see that blackboard bold is in stix-mathbb. We can go backwards and look for \mathbb in stix2.sty to see

\DeclareSymbolFontAlphabet{\mathbb}  {symbols3}

Then, looking for symbols3,

\DeclareSymbolFont{symbols3}      {LS1}{stix2bb}   {m} {n}

Good, we can even avoid defining new font encodings by looking in ls1stix2bb.fd and the relevant lines are

\DeclareFontFamily{LS1}{stix2bb}{\skewchar\font127 }
\DeclareFontShape{LS1}{stix2bb}{m}{n} {<-> stix2-mathbb}{}

Here's the complete code:

\documentclass{article}
\usepackage{amsmath}

\DeclareFontFamily{U}{stix2bb}{}
\DeclareFontShape{U}{stix2bb}{m}{n} {<-> stix2-mathbb}{}

\NewDocumentCommand{\stixbbdigit}{m}{%
  \text{\usefont{U}{stix2bb}{m}{n}#1}%
}
\newcommand{\bbzero}{\stixbbdigit{0}}
\newcommand{\bbone}{\stixbbdigit{1}}

\begin{document}

$A+\bbzero\ne\bbone$

\end{document}