Pi Number Tie, Necktie, Mathematician Gift, Mathematics, Math Teacher Gift.
The number π (/paɪ/) is a mathematical constant. Originally defined as the ratio of a circle's circumference to its diameter, it now has various equivalent definitions and appears in many formulas in all areas of mathematics and physics. It has been represented by the Greek letter "π" since the mid-18th century, though it is also sometimes spelled out as "pi". It is also called Archimedes' constant.
Pi number printed on microfiber tie with shiny satin look and feel.Tie size: Length: 58" Width: 3.25"