A popular question in Christmas quizzes asks how many gifts were sent, and received, altogether in the carol The Twelve Days of Christmas.
So on day 1 (sing the song) it was 1
On day 2 (sing the song) it was 2 plus 1 = 3
On day 3 plus 2 plus 1 = 6
….
What is the total after 12 days: 1 plus 3 plus 6 …?
Now, what if there were 365 days of Christmas? What would the grand total be then?