The Log of History

in #math8 years ago

In second grade (I was eight years old that year), my teacher informed us that we would be memorizing "the times tables" from 1x1 to 12x12 that year. I missed the "that year" part and thought we needed to know them that week! I wrote out each set of numbers carefully and fell asleep that night memorizing them. I still remember having to count up from 7x7=49 to 7x8=56 several times. For some reason, 7x8 just wouldn't stick in my memory. But I succeeded! I memorized them all... and spent the rest of the year during math times bored out of my skull. I think. Second grade memories have gotten a bit fuzzy.

A few years ago I decided I wanted to memorize logarithms (in base 10) as well. Only... the pattern was even less sticky than the times tables. I just couldn't seem to get the numbers to stick in my head.

However, I had enjoyed playing a history game at grocery stores. When paying cash, if I got less than $20 in change, I would try to treat the number as a year and see if I could remember anything that happened that year. So $10.00 became the year 1000 A.D. (or C.E. if you prefer) and I would remember that was the year Leif Erikson got blown off course and landed in Vinland. $19.28 became 1928, the year the stock market crash began the Great Depression.

I noticed that if I multiplied the logarithms by 1000, I got something that looked like a date. 1000xLog(7) becomes the year 845, and 1000xLog(11) become the year 1041. I began looking up events that happened in these years, trying to get the numbers to stick in my head. I'll post what I've found here in a series of "Log of History" posts. Maybe treating these numbers as dates will help someone else remember the logarithms too!

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Yes, today they seem to spend an aeon getting through the table up to, possibly, 12. Do it quickly when young and kids won't forget. I did it myself with my daughter - don't rely on schools.

Turning logs into dates is an interesting mnemonic technique - you must have a lot of spare mental energy! You're a biologist, is that right? What field?

A local fellow I know had a math teacher who was paying attention. The math teacher noticed that this guy had an easy time with multiplication tables and so he made him memorize them up to 50x50! I wish I'd had a teacher who had pushed me like that!

I don't know about spare mental energy... it's more like I'm prone to distractions. My family just thinks it's funny that I'm distracted by math!

I started off wanting to be a desert ecologist, so I went to work with a big-name desert ecologist and discovered that digging ditches in the hot desert sun was not going to work for me. After that I went into lab work, and gradually made my way from evolutionary biology to microbial genetics. The most exciting thing I did was probably working in a Biosafety Level 3 facility with things like Western Equine Encephalitis. Now I teach at a community college. It's not as dangerous, but seeing the students make connections is in some ways more exciting than making connections myself!