15×

15× is a notation that expresses multiplication by the number 15. The × symbol is read as "times" or "multiplied by," so 15×y means fifteen times y, and 15×2 equals 30. In mathematics, 15× is used as a factor; the expression 15×a can denote a product; 3×5=15 is an example.

Beyond basic arithmetic, 15× is used to describe magnification or scale in science and engineering. For example, 15× magnification means an image appears 15 times larger than the original; 15× scale means a model is enlarged fifteenfold.

In typography, × is a distinct character, Unicode U+00D7; it differs from the letter x. In plain text or sources with limited character sets, an asterisk (*) or the letter x may be used instead.

Historically, the times sign × originated in early modern mathematics as a multiplication symbol, derived from a stylized cross rather than the letter x.