To add functionality and different looks to a Google sheet, use ________.

The correct answer is add-ons, which enhance Google Sheets by providing additional features and functionalities beyond the basic capabilities of the platform. These add-ons can be installed from the Google Workspace Marketplace and include various tools for different purposes, such as advanced data analysis, project management, and enhanced visualization options. They allow users to customize their sheets significantly, enabling integrations with other applications and services, which can streamline workflows and improve efficiency.

While functions provide specific calculations or operations within cells, they do not alter the Google Sheets interface or add new features; rather, they enhance the data manipulation aspect. Templates offer pre-designed layouts and styles but do not inherently add functionality in the same way that add-ons do. Macros are used to automate repetitive tasks within Google Sheets but do not necessarily provide an array of functionalities that enhance the overall user experience like add-ons do. Thus, add-ons are the most appropriate choice for expanding both functionality and appearance in Google Sheets.