Writing Helpers
Helpers allow you to add additional functionality to your templates beyond what is included out-of-the-box in Ember. Helpers are most useful for transforming raw values from models and components into a format more appropriate for your users.
For example, imagine we have an Invoice model that contains a totalDue attribute, which represents the total amount due for that invoice. Because we do not want our company to go out of business due to strange JavaScript rounding errors,