<story><title>Is there any point to the 12 times table?</title><url>http://blog.wolfram.com/2013/06/26/is-there-any-point-to-the-12-times-table/</url></story><parent_chain><item><author>btilly</author><text>Easy divisibility is the reason why when we switched to metric, the one thing that didn&amp;#x27;t switch is time.  Which means that, for example, converting from m&amp;#x2F;s to km&amp;#x2F;h is a mess.  (You have to multiply by 3.6, can you easily do that in your head?)&lt;p&gt;With a base 12 version of everything you would have 1&amp;#x2F;12 of a day being 2 hours, 1&amp;#x2F;144 of a day is 10 minutes, and 1&amp;#x2F;1728 of a day is 50 seconds.  These units would give us both easy divisibility and are close enough to existing time units to make sense.&lt;p&gt;This change would mean we have to memorize a 12 times table rather than a 10 times table.  But in base 10 a 10 times table has easy patterns for 1, 2, 5, 9 and 10.  A 12 times table has repeating patterns for 1, 2, 3, 4, 6, 8, 9, 11 and 12.  The result is that a 12 times table in base 12 is actually less work to memorize than a 10 times table in base 10.&lt;p&gt;In the long run this transition would be a clear win.  But it isn&amp;#x27;t enough of one compared to the transition to ever make sense to initiate.</text></item><item><author>zeveb</author><text>Twelve has more divisors than ten (1, 2, 3, 4, 6 &amp;amp; 12 vs 1, 2, 5 &amp;amp; 10).  If we were really smart, we&amp;#x27;d switch from base 10 to base 12: many more &amp;#x27;decimals&amp;#x27; (really duodecimals) would be non-repeating.  One can very quickly count by twelves on the joints of one&amp;#x27;s fingers, using the thumb as an index (0-143 is a much larger range than 0-10, and it&amp;#x27;s easier to hold one&amp;#x27;s hands in the shape necessary).  If we were really smart, we&amp;#x27;d switch from base 10 to base 12: many more &amp;#x27;decimals&amp;#x27; (really duodecimals) would be non-repeating.&lt;p&gt;And then there are measures like a gross (144) and a great gross (1,728).  Part of the reason for these traditional measures is that they are more flexible than base-10 measures: an eighth-gross or a third-gross are both integer quantities, unlike an eighth-hundred or third-hundred.</text></item></parent_chain><comment><author>mark-r</author><text>In high school I calculated a system of decimal time periods and equated them to hours&amp;#x2F;minutes&amp;#x2F;seconds, just for fun. I realized it would never work when 1&amp;#x2F;100 of a day came out to 14.4 minutes; the TV stations would need to remove 72 seconds of advertising from every half hour show, something they would &lt;i&gt;never&lt;/i&gt; do.</text></comment>
<story><title>Is there any point to the 12 times table?</title><url>http://blog.wolfram.com/2013/06/26/is-there-any-point-to-the-12-times-table/</url></story><parent_chain><item><author>btilly</author><text>Easy divisibility is the reason why when we switched to metric, the one thing that didn&amp;#x27;t switch is time.  Which means that, for example, converting from m&amp;#x2F;s to km&amp;#x2F;h is a mess.  (You have to multiply by 3.6, can you easily do that in your head?)&lt;p&gt;With a base 12 version of everything you would have 1&amp;#x2F;12 of a day being 2 hours, 1&amp;#x2F;144 of a day is 10 minutes, and 1&amp;#x2F;1728 of a day is 50 seconds.  These units would give us both easy divisibility and are close enough to existing time units to make sense.&lt;p&gt;This change would mean we have to memorize a 12 times table rather than a 10 times table.  But in base 10 a 10 times table has easy patterns for 1, 2, 5, 9 and 10.  A 12 times table has repeating patterns for 1, 2, 3, 4, 6, 8, 9, 11 and 12.  The result is that a 12 times table in base 12 is actually less work to memorize than a 10 times table in base 10.&lt;p&gt;In the long run this transition would be a clear win.  But it isn&amp;#x27;t enough of one compared to the transition to ever make sense to initiate.</text></item><item><author>zeveb</author><text>Twelve has more divisors than ten (1, 2, 3, 4, 6 &amp;amp; 12 vs 1, 2, 5 &amp;amp; 10).  If we were really smart, we&amp;#x27;d switch from base 10 to base 12: many more &amp;#x27;decimals&amp;#x27; (really duodecimals) would be non-repeating.  One can very quickly count by twelves on the joints of one&amp;#x27;s fingers, using the thumb as an index (0-143 is a much larger range than 0-10, and it&amp;#x27;s easier to hold one&amp;#x27;s hands in the shape necessary).  If we were really smart, we&amp;#x27;d switch from base 10 to base 12: many more &amp;#x27;decimals&amp;#x27; (really duodecimals) would be non-repeating.&lt;p&gt;And then there are measures like a gross (144) and a great gross (1,728).  Part of the reason for these traditional measures is that they are more flexible than base-10 measures: an eighth-gross or a third-gross are both integer quantities, unlike an eighth-hundred or third-hundred.</text></item></parent_chain><comment><author>yes_or_gnome</author><text>I am in the process of reading &amp;#x27;The Story of French&amp;#x27; by Nadeau and Barlow. There&amp;#x27;s a chapter on how France was able to push their influence, during the renaissance, to get the world to switch to the metric system. Prior to developing the metric system, France had no standard for the pound; unlike England. This was the height of enlightenment in France, so the reformers wanted to replace the Gregorian Calendar with a metric time. I believe they wanted to call it the Republic Calendar; rather,  the equivalent in french. So, they commissioned a poet to rename the months of the year, keeping twelve months of 30 days, with 5 or 6 ambiguous days at the end of the year. However, the major downfall was moving to a 10-day week which reduced the &amp;#x27;weekend&amp;#x27; (not that it was called that) from 1 day out of a 7 day week to a 1-in-10. The plan was to have poetic names for the days of the week, but they felt that they were push their luck so instead they went with ordinal numbers.&lt;p&gt;The only country to actually use the calendar was, of course, France for 16(!?) years until Napoleon repealed it during his imperial reign.&lt;p&gt;&lt;a href=&quot;https:&amp;#x2F;&amp;#x2F;en.wikipedia.org&amp;#x2F;wiki&amp;#x2F;Metric_time&quot; rel=&quot;nofollow&quot;&gt;https:&amp;#x2F;&amp;#x2F;en.wikipedia.org&amp;#x2F;wiki&amp;#x2F;Metric_time&lt;/a&gt;&lt;p&gt;Anyone, feel free to correct me. I, literally, just read about this (fascinating) subject a couple nights ago. I haven&amp;#x27;t had time to independently follow up on the topic, but I plan to do so soon.&lt;p&gt;Amendum: A better link, &lt;a href=&quot;https:&amp;#x2F;&amp;#x2F;en.wikipedia.org&amp;#x2F;wiki&amp;#x2F;Decimal_time#France&quot; rel=&quot;nofollow&quot;&gt;https:&amp;#x2F;&amp;#x2F;en.wikipedia.org&amp;#x2F;wiki&amp;#x2F;Decimal_time#France&lt;/a&gt;</text></comment>