LaTeX/C2/Numbering-Equations/English

Initialisation:

Copy numbers.tex into align.tex Both numbers.tex and align.tex should be sized Both should be opened in Texworks Both should be at the first line align.tex should be below numbers.tex Compile align.tex and get align.pdf align.pdf should be sized align.pdf should be scrolled all the way to the top num-slides.pdf should be at the first slide All should be arranged, as recorded in the tutorial numbers.tex should be directly below the slides file Blank web browser with search “latex multi” The resulting google page should be in right zoom ltxprimer pdf file should be open in the first page The name of the ltxprimer.pdf should be seen ltxprimer pdf file should be zoomed appropriately Check that you have Internet access

Visual Cue	Narration
Opening slide	Welcome to this tutorial on numbering equations using LaTeX. My name is Kannan Moudgalya.
Learning objectives slide	In this tutorial, we will learn- How to put equation numbers How to remove them How to correctly reference equations How to use the information on the web
System requirements slide	One may use any of Linux, Windows or a Mac operating system. One needs LaTeX. I shall use TeXworks.
Prerequisites slide Press Down arrow Down arrow	What are the prerequisites? One needs to be familiar with spoken tutorials that introduce LaTeX. We recommend the use of the Side-by-Side method. This information is available at the Spoken Tutorial webpage.
Additional material slide Show equation.tex Show ltxprimer pdf file Back to slides file, press down arrow.	I shall use the following files: numbers.tex, which you can see here. ltxprimer pdf file from TUG India. It is here. These are available as Code files along with this tutorial. With these files, you will be able to practise along with me. If you don't have these files, please download them from the Spoken Tutorial website.
Open numbers.tex	Let us begin the tutorial.
	Let us learn how to create numbers for equations in LaTeX. I have already opened the file numbers.tex in TeXworks.
Point to the title align.tex	I have saved it as align.tex to use in this tutorial.
	I will keep the numbers.tex file intact, and not change it.
Narration only	Please pause the tutorial, make a copy of numbers.tex and open it. Whenever you want to start afresh, you can make a new copy of numbers.tex I recommend this method whenever a code file is given with ANY spoken tutorial.
Open align.tex	Let me open align.tex
Press the Typeset key	Let us compile this file by pressing the Typeset arrow at the top left hand corner. You can see the pdf file on the right.
Point to the equations	These equations do not have numbers.
Remove the * from align	We can put equation numbers by removing the star from the align star.
Remove the * from begin align and end align	Remove the star from both begin and end statements. Forgetting it in the end statement is a common mistake.
Put * in end align statement	Let’s see what happens if I forget to remove it from the end align statement.
Compile	Let us compile.
Error message	It gives an error message- begin align ended with align star.
Remove the * from end align	Let us remove the star from end align also. Let us abort typesetting and compile. We now have equation numbers.
Write a statement that makes use of the number of the second equation.	Let us now refer to the second equation in the running text. Put the number 2 after the word equation.
Compile	Compile. We see number 2 in the running text.
Narration	I will now show you how to remove the equation number of one equation.
Point to first equation	Suppose that we don’t want a number for the first equation.
Put \nonumber at the end of first equation and compile	Go to the end of the first equation, but before intertext, and put back slash nonumber.
Highlight \nonumber	Please note that nonumber is one word. Do not forget the back slash at the beginning.
Compile >>Point to 1st equation	On compiling, the number disappears from the first equation.
Highlight the 2nd equation	One consequence is that the second equation is now numbered as one.
Highlight equation 2 in the running text	Unfortunately, the reference to the second equation has become wrong in the text.
Narration only	Can we prevent such mistakes even if we have to add or remove equations? Such a requirement occurs frequently while writing reports, theses, papers, etc.
Put \label{PID}	It is possible to do this through the label statement. We have seen this in a previous tutorial also. Let me put slash label PID at the end of the second equation, but before end align.
Put \ref{PID}	Replace 2 in the running text with slash ref PID as I do now.
Compile	After compiling once, two question marks appear against the equation number.
Compile again	On compiling twice, the question marks get replaced by the correct number.
Remove \nonumber	Let us change the equation number once again by removing nonumber.
Compile twice.	Compile twice to get correct answers.
Change PID to pid in ref command, but don’t compile Put it back as PID in label command Compile	The variable in the ref and label commands have to be identical. Check what happens if you change PID in the ref command to lowercase. Leave the PID in uppercase in the label command and compile.
Point to question mark	We get question mark here because this lowercase pid is not defined. I will put pid back in uppercase and compile.
Narration	I will now show you how to take help from the Internet.
Delete all the text in the tex file	Before that, I am going to delete everything in the tex file. If you don’t like it, you can open a new file.
Narration only	To do this part, you need access to Internet. If you don’t have this access now, you may try this part later.
Go to Google page >> type LaTeX multiline in the search bar	Let me go to a web browser. Let me do a web search on the topic of LaTeX multiline.
Hover on stackexchange	The very first hit is on stackexchange. Let me click this “How to align...”.
Scroll down the page	If you scroll down this page, you will see a question and several answers. Most answers present a complete code.
Copy from top to bottom, not from bottom	Let us copy the code that says 58. This number may be different when you access this page. Below this, the pdf file created by this code is shown. Let me paste it on the tex file.
Compile	Let us compile the tex file. You can check the output in this pdf file to be identical to what we saw in stackexchange.
	Please try all commands explained in this web page and understand them.
Remove the text between the begin and end document	Next let me delete everything inside the document environment. Let us now open the ltxprimer pdf file that we have provided with this tutorial. You can practise this part even if you don’t have web access.
Scroll down the page >> Contents	Let us scroll and go to Contents.
Click on Typesetting Mathematics	Let us click “Typesetting Mathematics”.
Point to the examples.	You can see many examples.
Go to page 87	Let us go to page 87.
Copy and paste the code	Let us copy “cases code” and paste it within the document environment.
Compile	On compiling it, we get the output given in ltxprimer.
Change equation* to align* >> Compile	You may change equation* to align*, and compile. We get identical results. I suggest that you spend a minute in understanding this example. I also suggest that you try more examples from ltxprimer.
	This brings us to the end of this tutorial.
What did we learn slide Press space	This page summarises what we learnt in this tutorial. Please recall each of these commands. This is your first assignment. Please do a search on these commands over the web, in ltxprimer, etc. Locate these examples and try them out.
More assignments slide	I will give some more assignments.
Assignment 2	We compiled twice to get correct numbers. Why should we compile twice? Hint: we saw this in an earlier tutorial. You can also locate an answer for this in ltxprimer.pdf file. Search for Cross References.
Assignment 3	Try examples from Chapter 8 of ltxprimer pdf file we saw earlier. Try to understand them.
Assignment 4	Try multiline examples from the Stackexchange web page we saw earlier.
About the ST slide Press the Enter key	I will now give some general information. This video summarises the Spoken Tutorial project.
Workshops slide	We conduct workshops using Spoken Tutorials.
Answers slide Press Space key Space Space Space Space twice	Do you have questions in THIS Spoken Tutorial? Please visit this site Choose the minute and second where you have the question Explain your question briefly Someone from our team will answer them You will have to register on this website to ask questions.
Where to post slide	For topics not covered in spoken tutorials, visit stackexchange at this address. This is a great place to get answers on LaTeX.
General questions slide	You may also have questions on our workshops, certificates, etc. For this, get in touch with us at this email address.
	Spoken Tutorial project is funded by MHRD, Government of India.
	Thanks for joining. Goodbye.

Contributors and Content Editors

Nancyvarkey, PoojaMoolya, Pravin1389