LaTeX doesn't show negative sign in exponent

Question

Writing the code

The weight decay was set to $1 \times {10^{−4}}$ for Model 8 and $5\times 10^{−4}$.

the negative sign is missing.

And these are the packages I'm using

\usepackage{jmlr2e}
\usepackage{indentfirst}
% Definitions of handy macros can go here
\usepackage{float}
\usepackage{underscore}
\restylefloat{table}
\newcommand{\dataset}{{\cal D}}
\newcommand{\fracpartial}[2]{\frac{\partial #1}{\partial  #2}}

Answer 1

The problem occurs because the symbol − that's used in both exponents is not a "normal" dash symbol, -. Instead, it is the Unicode symbol U+2212, the "math minus" symbol. (Did you maybe copy and paste the input from some other source?)

Here are three remedies:

• Switch to either XeLaTeX or LuaLaTeX and load either the fontspec package or the unicode-math package (which loads fontspec automatically).

• If you need to use pdfLaTeX, add the following instructions to your preamble:

  \usepackage[utf8]{inputenc}
  \DeclareUnicodeCharacter{2212}{-}
  

• Finally, consider simply replacing all instances of − with -. (That's what's done in the code below.)

\documentclass{article}

\begin{document}

\section*{Your code}
The weight decay was set to $1 \times {10^{−4}}$ for Model 8 and $5 
\times 10^{−4}$.

\bigskip

\section*{Correct code}
The weight decay was set to $1 \times {10^{-4}}$ for Model 8 and $5 
\times 10^{-4}$.

\end{document}

Answer 2

I fixed your codes as follows:

The weight decay was set to $1 \times {10^{-4}}$ for Model 8 and $5\times 10^{-4}$.

And the following is the PDF style.

The reason that why your − can't be complied may be that you type it not in English typewriting. Please make sure you are under English typewriting when you type codes in math environment.

Answer 3

shorter and correct with use siunitx package:

\documentclass{article}
\usepackage{siunitx}

\begin{document}
The weight decay was set to \num{1e-4} for Model 8 and \num{5e-4}.
\end{document}