In the song "The Twelve Days of Christmas", the singer receives 364 gifts in total.
Day 1: 1 partridge in a pear tree = 1 gift
Day 2: 2 turtle doves + 1 partridge = 3 gifts
Day 3: 3 French hens, 2 move doves, and yet another partridge = 6 gifts
Day 4: 4 calling birds + all of day 3's stuff = 10 gifts
Day 5: 5 + day 4's stuff = 15
Day 6 : 6 + 15 = 21 gifts
Day 7: 7 + 21= 28
Day 8: 8 + 28 = 36
Day 9: 9 + 36 = 45
Day 10: 10+45 = 55
Day 11: 11+ 55 = 66
Day 12: 12 + 66 = 78
add them up = 364 gifts
The number of gifts received on day number n is (n² + n) ÷ 2. For example, on day twelve, there are (12² + 12) ÷ 2 = 78 gifts
The total: