Table of Contents numbering in decimals?

Question

I have created my first LaTeX document, its very small and have 4 sections. The problem is the numbering is in decimals and looks a little odd, I have searched every where, I'm sure its a simple fix.

Current form:

0.1 introduction
0.2 aims
0.3 Objectives
0.4 summary

How can I change it to normal numbering, like 1, 2, 3, ...?

Here is my basic code:

\documentclass[12pt]{report}
\usepackage[parfill]{parskip}
\usepackage[round]{natbib}
\renewcommand\bibname{References}

\begin{document}
\maketitle

\renewcommand\thepage{}
\pagenumbering{roman}
\tableofcontents
\newpage
\renewcommand\thepage{\arabic{page}} 

\newpage

\section{Introduction}
The text starts here

Answer 1

The report document class provides \chapter (and more), just like the book document class. And, as a consequence, it defines all sectional heading numeration relative to this commonly-used top-level sectional heading \chapter. Yes, there is another level higher called \part, but that is not used that often.

Numbered section titles have \thechapter.\arabic{section} by default; numbered subsection titles have \thesection.\arabic{subsection}; etc. This defines a hierarchical numbering structure, which is typical from what you see in books. Overriding this is possible by merely removing the chapter counter from being printed with the section counter:

\renewcommand{\thesection}{\arabic{section}}

The \the<counter> refers to the printing of the counter <counter>. The above command changes that printing behaviour to just print the section counter using the \arabic style. Since all the lower-level sectional counters print using the hierarchical structure, only this definition is needed for the rest to work as expected.

A better (perhaps preferred) alternative to this is to use a document class that does not support chapters. This is provided by the article document class. Since it does not provide \chapter, \section is the top-level sectional heading, making all counters necessarily be numbered hierarchically according to it.

Answer 2

\renewcommand{\thesection}{\arabic{section}} may do, depending on your \documentclass.

Answer 3

Without a minimum working example, it is difficult to tell exactly what the problem is. For instance, with the book class:

\documentclass{book}
\begin{document}

\section{section}
\section{section}
\section{section}
\end{document}

you get

0.1 section

0.2 section

0.3 section

But, if you use \chapters:

\documentclass{book}
\begin{document}
\tableofcontents
\chapter{Chapter}
\chapter{Chapter}
\chapter{Chapter}
\end{document}

you get

1 Chapter

2 Chapter

3 Chapter