You'll see the same card if you search for [what's the tip for 30 dollars], [tip for $50] or if you use Google Voice Search.
You could obtain the same results using Google's regular calculator feature, but it's a little bit more complicated. Google's widget shows the same information as the top search result for [tip calculator].
"A tip (also called a gratuity) is a sum of money customarily tendered to certain service sector workers for a service performed or anticipated. Tipping and the amount are a matter of social custom and social practices vary between countries and settings. In some locations tipping is discouraged and considered insulting and in some locations tipping is expected from customers. The customary tip can be a specific range of monetary amounts or a given percentage of the bill," informs Wikipedia. For example, in the US the tip is 15-20%, in the UK it's usually 10%, in Germany it's 2-10%, while in Asia there is no tipping.
{ via +Google }