In algebra, multiplying "y" by "z" (or "y" times "z") can be written in 4 ways: "y × z", "y * z", "y·z", or just "yz". The multiplication symbol "×" is usually not used, because it looks too much like the letter x, which is often used as a variable. Also, when multiplying a larger expression, parentheses can be used: "y" ("z+1").