• Replies 21 replies
  • Subscribers 28 subscribers
  • Views 2755 views
  • Users 0 members are here
Options
Related
Hints and tips
  • To quote someone's message, first select/highlight the relevant text, and then use the Quote button that appears
  • To "mention" someone, type @ followed by the start of the forum name, and choose from the list; that person will get a notification of being mentioned

Log Tables

lostmyway

While I have a good idea how log tables work, I'm still in the dark as to how they are compiled.

I gather some bloke name 'Napier' originally invented them but what method did he use?

Any mathematicians' contributions would be appreciated. 

Parents

  • Trainspotter said:

    [quote][/quote]

    OK, for instance, how would I work out the log of 50 to base 10?

    Easy if you know what log 2 is which is .3010 (to four decimal places)

    Subtract this from log 100 which makes 1.6990

    (You can then work out a few other logs, such as Log 5, Log 8, Log 16, Log32, Log 25, Log 12.5, etc)

    But the hard part is calculating log 2 rather than looking it up in a table .... as you need to know what power to raise 10 to make 2! Easy with a computer but very difficult and time consuming without!

    I think I'm gonna have to go back to basics, Trainspotter.

    I'm trying to jump into something unprepared but thanks for trying to teach me.

Reply

  • Trainspotter said:

    [quote][/quote]

    OK, for instance, how would I work out the log of 50 to base 10?

    Easy if you know what log 2 is which is .3010 (to four decimal places)

    Subtract this from log 100 which makes 1.6990

    (You can then work out a few other logs, such as Log 5, Log 8, Log 16, Log32, Log 25, Log 12.5, etc)

    But the hard part is calculating log 2 rather than looking it up in a table .... as you need to know what power to raise 10 to make 2! Easy with a computer but very difficult and time consuming without!

    I think I'm gonna have to go back to basics, Trainspotter.

    I'm trying to jump into something unprepared but thanks for trying to teach me.

Children
No Data