Mantissa

A common logarithm, in general, consists of an integer, which is called the characteristic, and a decimal (usually endless), which is called the mantissa. The characteristic of any number may be determined from the following rules ... 

Mantissa of a Common Logarithm of a Number. An important consequence of the use of base 10 is that the mantissa of a number is independent of the position of the decimal point. Thus 93 600, 93.600, 0.000 936, all have the same mantissa. Hence in Tables of Common Logarithms only mantissas are given. A five-place table gives the values of the mantissa correct to five places of decimals. 

When connecting numbers to logarithms, use as many decimal places in the mantissa as there are significant digits in the number. 

When finding the antilogarithm, keep as many significant digits as there are decimal places in the mantissa. 

Mantisse,/. (Math.) mantissa, manuell, a. manual, hand. 

This must be written in the usual form containing a negative characteristic and a positive mantissa ... 

The distinction between the characteristic and the mantissa is important when we have to decide how many significant figures to retain in a calculation that includes... 

Values are given as (mantissa exponent) for example 2.428 -1 reads 2.428. 10" ... 

Note Significant figures for logarithms is equal to the number of significant figures in the mantissa. 

Number of digits in mantissa of log x = number of significant figures in x ... 

A logarithm is composed of a characteristic and a mantissa. The characteristic is the integer part and the mantissa is the decimal part ... 

In the conversion of a logarithm into its antilogarithm, the number of significant figures in the antilogarithm should equal the number of digits in the mantissa. Thus,... 

There are two significant figures in the concentration of Ag because there are two significant figures in Ksp. The two figures in [Ag+] translate into two figures in the mantissa of the p function, which is correctly written as 14.84. 

We could justify three significant figures for the mantissa of pAg+, because there are now three significant figures in Ag+j. For consistency with earlier results, we retain only two figures. We will generally express p functions in this book with two decimal places. 

MALDI See matrix-assisted laser desorption/ionization. mantissa The part of a logarithm to the right of the decimal point. 

The logarithm of a number consists of two parts, called the characteristic and the mantissa. The characteristic is the portion of the log that lies before the decimal point, and the mantissa is the portion that lies after the decimal point. The significance of separating a logarithm into these two parts is evident when you apply the logarithm laws to the logs of numbers such as 2000, and 2, and 0.000002. 

Note that the characteristic is determined by the power to which 10 is raised (when the number is in standard scientific notation), and the mantissa is determined by the log of the lefthand factor (when the number is in scientific notation). It is these properties that make it so easy to find the logarithm of a number using a log table. Here is how you can do it. 

Look up the mantissa in the log table. It is the log of the lefthand factor in scientific notation, which is a number between 1 and 10. The mantissa will lie between 0 and 1. 

The log tables of this book show only three digits for N. If you want the log of a four-digit number, you must estimate the mantissa from the two closest values in the table. This process is called interpolation. For example, to find the log of 2032, you would proceed as follows. 

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