1-1 is a mathematical expression that evaluates to: 0 (number) The mathematical expression 1-1 equals 0. The simple equation of one minus one represents the fundamental concept of subtraction, where taking a single quantity away from an identical quantity leaves nothing behind. In the realm of arithmetic, this zero acts as a profound placeholder and a symbol for complete absence or equilibrium.
The term 1-1 may refer to: New Year's Day, a public holiday in many countries, held annually on the first of January Schweizer SGP 1-1, an American glider design World 1-1, the first level of Nintendo's Super Mario Bros.
See also 1:1 (disambiguation) 1+1 (disambiguation) One-to-one (disambiguation)