Error occurs when entering values that don't match Data Validation criteria
Data validation restricts cell entry based on predefined rules. Rules can allow text, numbers, dates, or specific ranges. Validation helps eliminate data entry mistakes
NULLIF(divisor,0) returns NULL when dividing by zero. COALESCE function can replace NULL with 0. WHERE clause can filter out zero values. CASE statement can handle zero values specially
Drop-down lists help users work more efficiently in worksheets. List items should ideally be in Excel table format. Data can be converted to table using Ctrl+T
Double-click cell to start typing list items. Use Alt+7 (PC) or Option+8 (Mac) for bullet points. For numbered lists, start with 1. or 1). Press Alt+Enter (PC) or Control+Option+Return to go to next line
Dropdown lists allow users to select items from predefined lists. Data Validation feature enables creating dropdown menus. Dropdown arrows appear next to cells for selection