(no subject)

[petmoosie]

Long summer days. With children.

Mrmoosie's family is visiting, so we are having a lot of fun, but getting totally off schedule.

I spent three hours today on a practice test for chemistry. I actually did quite well, so I am feeling more confident. It was long and exhausting, however.

Not really sure how to take logarithms without a table of them or a calculator. Is this something I learned in math, or never learned? I do remember using the tables of logarithms.

Comments

[metageek.livejournal.com]

I don't know any practical way to do logarithms except a table (and interpolation) or a calculator. I can approximate, sometimes, by knowing the common log of 2, 3, and 5, and factoring the number I need, or one near it. That's really only good for mental back-of-the-envelope work, though.

[petmoosie.livejournal.com]

well, yes! knowing 2, 3, and 5 gets me 2, 3, 4, 5, 6, 8 and 9. And I already know 1 and 10, of course. I'm mostly working with pHs and related concepts, so that is all log base 10.

Is log base 10 the same thing you mean by common log?

I can surely memorize three numbers!

[metageek.livejournal.com]

Is log base 10 the same thing you mean by common log?

Sorry for the delay...

Yes. I just wrote "common log" because I was on my tablet and didn't want to jump through the hoops to write log10, and had forgotten the word "base".