An index accompanies this symbol that encompasses all the essential terms to be considered in the sum. Hence, the summation symbol has a vital role in mathematical expressions. So, let’s look at the methods for creating and using summation in LaTeX.

**How to Create and Use a Summation Symbol in LaTeX?**

To write a summation symbol in LaTeX, you can use codes like \sum, \sigma, etc. Let’s start with the simple examples and use these source codes to write the summation symbols:

\begin{document}

Either you can use:

$$\Sigma x_i$$

Or else:

$$\sum x_i $$

\end{document}

**Output**

Similarly, you can create different types of mathematical equations using the following source codes:

\begin{document}

$$ \Sigma A_x $$ \\

$$ \Sigma \frac{4}{(A_x)+(B_x)} $$ \\

$$ \Sigma_{x=1}^M (A_x) $$ \\

$$ \sum A_X $$ \\

$$ \sum \frac{4}{(A_x)+(B_x)} $$ \\

$$ \sum_{x=1}^M (A_x) $$ \\

\end{document}

**Output**

Let’s take another example that contains a summation symbol with the above or below limit condition:

\usepackage{amsmath}

\begin{document}

\[ \sum_{i=2}^{M}A_i = A_4 + A_3 + A_2 + A_1+ \cdots + A_M \]

\end{document}

**Output**

You can add multiple expressions under the summation using the \atop source code:

\begin{document}

\[\sum_{ 1 \leq x \leq A \atop 1 \leq y \leq A }B_{x,y}\]

\end{document}

**Output**

Now let’s write the source code to use multiple summation symbols in the mathematical expression:

\begin{document}

$$\sum\limits_{X=1}^A\sum\limits_{Y=4}^B C_X D_Y $$

$$\sum\limits_{X=1}^\infty\sum\limits_{Y=4}^\infty \frac{5}{A^{X+Y}}= P$$

$$\mathit{if}|\mathit{B}|>1$$

\end{document}

**Output**

**Conclusion:**

This was the concept of summation and the methods for writing and using the summation symbol in LaTeX. We have included two different codes and examples to explain everything easily.