Curated Video
HOLIDAY RIDDLE - In The "12 Days Of Christmas," How Many Total Gifts Are Given?
You may remember the song "12 Days of Christmas" in which each day you get N gifts, plus all the gifts from the preceding days. How many gifts are given in total? What's a general formula? Algebraic proof...
Curated Video
When Is Christmas? Mentally Convert Date To Day Of The Week
January 1, 2016 is a Friday. When will Christmas be in 2016? What about Christmas in 2055? You can do this in your head! Blog post (text explanation): http://wp.me/p6aMk-4qQ Doomsday Rule (previous video):...
Curated Video
Calculate The Day Of The Week For Any Date Until 2099
January 1, 2015 is a Thursday. When will Christmas be in 2015? You can do this in your head! Doomsday Rule http://en.wikipedia.org/wiki/Doomsday_rule Calculating the day New Years (1/1) occurs https://www.youtube.com/watch?v=7iZ1TlqcqVc...