Mammoth Memory

The log tables

So how did we convert `69.31\times57.43` into `10^(1.8408)\times10^(1.7591)`

We use log tables            (see reference log tables above)

 

Look up `69.31`

Logs only work between `1` and `10`

And so `69.31` is `10^1\times6.931`

So we look up `6.931`

Here is part of the log table:

Look up 69.31.jpg

`0.8407 + 1` (to the last digit) = `0.8408`

Log table of `6.931 = 0.8408`

So `69.31 = 10^1\times10^0.8408`

      `69.31 = 10^1.8408` (adding indices)

 

Look up `57.43`                                                       

Logs only work between `1` and `10`

And so `57.43` is `10^1\times5.743`

So we look up `5.743`

Here is part of the log table:

Look up 57.43.jpg

`0.7589 + 2` (to the last digit) = `0.7591`

Log table of `5.743 = 0.7591`

So `57.43 = 10^1\times 10^0.7591`

      `57.43 = 10^(1.7591)` (adding indices)

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