A microblog post by @kareem_carr saying “as soon as i saw they were using asterisks for multiplication symbols, i knew we were in trouble”, with an image from the “Office of the United States Trade Representative (Executive Office of the President)” showing the mathematical formula $\Delta \tau_i = \frac{x_i - m_i}{\varepsilon * \varphi * m_i}$. The formula show asterisks (*) instead of multiplication signs (×).
Typically you’d use either nothing (just put the symbols next to each other) or in cases where that would be unclear, you’d use the centered dot ⋅