Exceljet

Quick, clean, and to the point

Apply or remove strikethrough formatting

Windows shortcut 
Ctrl5
Mac shortcut 
X

This shortcut toggles strikethrough on and off for the current selection.

This is the best Excel training site I have ever seen. -Kedy
Excel foundational video course
Excel Pivot Table video training course
Excel formulas and functions video training course
Excel Shortcuts Video Course
Excel Charts video training course