# how to show step by step calculation in beamer (effect of animation)

Question: I have an example of maths. My question is how can i display step by step solution in presentation i mean i would like to add animation effect.

MWE:

\documentclass[12pt]{beamer}
\usepackage{xcolor}
\usetheme{AnnArbor}
\usecolortheme{beaver}
\usepackage{enumitem}
\usefonttheme{professionalfonts} % using non standard fonts for beamer
\usefonttheme{serif} % default family is serif
\usepackage{setspace}
%make new line after item
\makeatother
\title[abc University]{\textbf{Example}}

\author[Prof. xyz]{}
\date[\today]{}
\begin{document}
\begin{frame}[t]{}
%\setstretch{2.5}
\begin{align*}
x^2 -2x-15 &=0&\8pt] x^2-5x+3x-15&=0&\\[8pt] x(x-5)+3(x-5)&=0&\\[8pt] (x-5)(x+3)&=0& \end{align*} \end{frame} \end{document}  ## 1 Answer The amsmath environments like align do not work with \pause. But you do not need them here either, a simple array does the job. So all you need to do then is to add \pause wherever appropriate. (I also added fleqn because this looks IMHO cleaner.) \documentclass[12pt,fleqn]{beamer} \usepackage{xcolor} \usetheme{AnnArbor} \usecolortheme{beaver} \usepackage{enumitem} \usefonttheme{professionalfonts} % using non standard fonts for beamer \usefonttheme{serif} % default family is serif \usepackage{setspace} \addtobeamertemplate{frametitle}{}{\vspace{-0.4em}} % decrease %make new line after item \makeatother \title[abc University]{\textbf{Example}} \author[Prof. xyz]{} \date[\today]{} \begin{document} \begin{frame}[t] \frametitle{Equations revealed step by step} \[ \begin{array}{@{}r @{{}={}} l@{}} x^2 -2x-15 &0\pause\\[8pt] x^2-5x+3x-15&0\pause\\[8pt] x(x-5)+3(x-5)&0\pause\\[8pt] (x-5)(x+3)&0 \end{array}
\end{frame}
\end{document}


An automatic animation can be obtained with \animate. The time the nth overlay is on display is set by \transduration<n>{...}, where ... is the time in seconds. This animation will play from overlay 2 on when viewed with Acrobat Reader in fullscreen mode.

\documentclass[12pt,fleqn]{beamer}
\usepackage{xcolor}
\usetheme{AnnArbor}
\usecolortheme{beaver}
\usepackage{enumitem}
\usefonttheme{professionalfonts} % using non standard fonts for beamer
\usefonttheme{serif} % default family is serif
\usepackage{setspace}
%make new line after item
\makeatother
\title[abc University]{\textbf{Example}}

\author[Prof. xyz]{}
\date[\today]{}
\begin{document}
\begin{frame}[t]
\frametitle{Equations revealed step by step}
\animate<2-5>
\transduration<2>{2}%
\transduration<3>{4}%
\transduration<4>{6}%
$\begin{array}{@{}r @{{}={}} l@{}} x^2 -2x-15 &0\pause\\[8pt] x^2-5x+3x-15&0\pause\\[8pt] x(x-5)+3(x-5)&0\pause\\[8pt] (x-5)(x+3)&0 \end{array}$
\end{frame}
\end{document}

• Great, once again you come forward for replying my question. Thanks a lot. Jun 1 '20 at 4:08
• Suppose I want to stop at any line for 2 or 3 minutes is it possible? Jun 1 '20 at 4:09
• @Maths4Sandy Ah, I thought this is a presentation in which you press a key when you want to see the next step. If you want to have an automatic animation, you could could use the \animate facility of beamer and use \transduration. I added an example.
– user194703
Jun 1 '20 at 4:21
• @Maths4Sandy If you remove the \pause commands, there will be no steps. Is this what you are asking?
– user194703
Jun 1 '20 at 4:53
• @Maths4Sandy This is how overlays on beamer work: technically these are several slides, however, when you present them, they look like an animation. You can use the animate package, where this is a bit hidden, but again it produces some pdf file for each step.
– user194703
Jun 1 '20 at 5:00