Checkmark is a symbol that some times we use but not available directly on the keyboard. To display a checkmark we need to use alt code. The alt code for checkmark is ALT+251.
Are you looking for √ (Checkmark) alt code?
To insert a checkmark in Excell, Windord, or Powerpoint (Microsoft Office Family). Insert Object and choose Wingdings font. Wingdings is in the default list font of Windows so you will find it without the need to add the font.