The Joy of 9
(2017, original release: 2007)
Nonfiction
eCourse
Details
PUBLISHED
The Great Courses, 2007
[San Francisco, California, USA] : Kanopy Streaming, 2017
[San Francisco, California, USA] : Kanopy Streaming, 2017
DESCRIPTION
1 online resource (streaming video file) (32 minutes): digital, .flv file, sound
ISBN/ISSN
1274169
LANGUAGE
English
NOTES
Title from title frames
Adding the digits of a multiple of 9 always gives a multiple of 9. For example: 9 x 4 = 36, and 3 + 6 = 9. Inmodular arithmetic, this property allows checking answers by "casting out nines." A related trick: mentally computing the day of the week for any date in history
In Process Record
Film
Originally produced by The Great Courses in 2007
Mode of access: World Wide Web
In English