#math trivia for #April26: #117 is one of 40 day-numbers divisible by 9 this year. How many also have digits that add up to 9? — Burt Kaliski Jr. (@modulomathy) April 26, 2012 Any number whose digits add up to a multiple of 9 is divisible by 9, and vice versa. Most of the day-numbers … Continue reading