**To make the math in beamer look like the usual LaTeX math, you only have to insert the following declaration in your preamble \usefonttheme[onlymath]{serif}.**

The following illustration is obtained with the standard Beamer font:

The following code corresponds generates the same content as above but with changing Math equations font style:

% Change Math font style in Beamer \documentclass{beamer} % Theme choice \usetheme{AnnArbor} % Change Math font \usefonttheme[onlymath]{serif} \begin{document} \begin{frame}{Change Math font style} \begin{block}{Pythagoras' theorem} If you square the two shorter sides in a right-angled triangle and add them together, you get the same as when you square the longest side (the hypotenuse): \[ x^2 + y^2 = z^2 \] where $x$ and $y$ are the two shorter sides and $z$ is the hypotenuse. \end{block} \textbf{Equations in Beamer: } \begin{align*} f(x) &= x^2\\ g(x) &= \frac{1}{x}\\ F(x) &= \int^a_b \frac{1}{3}x^3 \end{align*} \end{frame} \end{document}

Here is the obtained results:

The declaration `\usefonttheme[onlymath]{serif}`

changes the math font of the beamer theme to serif. You can also change the font of the base text and make different combinations tuning both. Here you can find a nice list of already compiled combinations of different text and mathematical fonts.