How can I sum two numbers in Latex with my own command? - sum

Question

I have to sum two numbers (integers) in LaTeX. I also have to "print" the process of sum. So it would look like 5+2=7 in text. Any ideas?
My code so far:
\newcommand{\Sum}
{\newcounter{cnt}
\setcountter{cnt}{1+1}
}

Answer 1

In LaTeX, first you have to define a counter with:
\newcounter{countername}
Then you can put a value in this counter with:
\setcounter{countername}{<value>}
where <value> is an integer. Or you can add one to this counter with:
\stepcounter{countername}
or you can add some arbitrary value to this counter with:
\addtocounter{countername}{<value>}
Then, to access this counter you use:
\value{countername}
so you can, for example, make calculations with this counter:
\setcounter{anothercounter}{%
\numexpr\value{countername}+10\relax%
}
Then, when you need to print the value of this counter to the pdf file, you can you the mighty \the:
\the\value{countername}
or you can use one of these:
\arabic{countername}
\roman{countername}
\Roman{countername}
\alph{countername}
\Alph{countername}

Answer 2

Perhaps a different syntax can be in order; instead of supplying each argument to calculate a sum, you can supply the operator with the operands. This allows you to be a little more flexible in terms of the input and also provide more functionality:
\documentclass{article}
\usepackage{xfp}
\NewDocumentCommand{\showcalculation}{o m}{$
\IfValueTF{#1}
{#1}{#2} = \fpeval{#2}
$}
\begin{document}
\showcalculation{7+3}
\showcalculation{1+2-3+4}
\showcalculation[22 \div 7]{22 / 7}
\showcalculation[10 \times 3^{7 - 7}]{10 * 3 ^ (7 - 7)}
\end{document}
The optional argument for \showcalculation uses a LaTeX formatting for the printable calculation.

Answer 3

I've managed to solve the problem.
\newcommand{\Sum} [2] {#1 + #2 = \the\numexpr #1 + #2 \relax \\}
And then I use my command as:
\Sum {7} {3}