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 (×).
Most of the time in math, you just put the symbols you want to multiply without anything between them, the multiplication is implicit, or if you really want to make it explicit, you put a dot or a cross. The only time you would use an * is when programming.