The phrase “seven seas” (sail the seven seas) has been used metaphorically since the 19th Century, to evoke all the waters or oceans of the world – and specifically the Arctic, Antarctic, North and South Pacific, North and South Atlantic and Indian Oceans.
On the seven-segment displays of pocket calculators and digital watches, 7 is the number with the most common glyph variation (1, 6 and 9 also have variant glyphs). Most calculators use three line segments, but on Sharp, Casio, and a few other brands of calculators, 7 is written with four line segments because, in Japan, Korea and Taiwan 7 is written as ? in the illustration to the right.
7 is considered a lucky number. There are 7 days of the week, 7 continents, 7 Wonders of the World, as well as 7 Deadly Sins.
Picture Credit : Google