How to calculate logarithms manually

We learn how to calculate logarithms of decimals and fractions as well as how to deal with cases for which the input value isn't an obvious power of the base. In particular we study the case in which the base is greater than the input value as well as cases as well as the case in which the base and input values aren't simple powers of each other, by finding a common base. Answer (1 of 23): Here is how to calculate logarithms by hand using only multiplication and subtraction. And this procedure produces digit by digit, so you can stop. Calculating Logarithms By Hand W. Blaine Dowler J Abstract This details methods by which we can calculate logarithms by hand. 1 De nition and Basic Properties A logarithm can be de ned as follows: if bx = y, then x = log b y. In other words, the logarithm of y to base b is the exponent we must raise b to in order to get y as the www.doorway.ru Size: KB.

Method: Choose a number very close to the original number that you can construct using factors whose logarithms you have learnt. Calculate the logarithm of this approximated number Calculate the percentage error and multiply by and add or subtract as appropriate. Now, is a number we can easily guess the logarithm from = a little over 3. In other words, 2^{10} = =. log(2^{10}) = log() =. 10*log(2) = log() = 3 + log() =. log(2) = + log()/ So the difficult part now is log(). Let’s use. We learn how to calculate logarithms of decimals and fractions as well as how to deal with cases for which the input value isn't an obvious power of the base. In particular we study the case in which the base is greater than the input value as well as cases as well as the case in which the base and input values aren't simple powers of each other, by finding a common base.

Example 1 Without a calculator give the exact value of each of the following logarithms. log If you want a general way to find logarithms without using But perhaps there is an easier way (without a calculator we need to think of. Isolate the logarithm to one side of the equation. Before you can solve the logarithm, you need to shift all logs in the equation to one side of the equal sign.