# Significant numbers

The doctrine of the approximate calculations **significant digits** are all numbers except zero, and zero, but if he stands between the other significant figures. So, in the days of 3700 and 0,0062 all zeros are insignificant. The numbers 105 and 2006, the zeros are significant figures. Among 0,0708 first two zero - insignificant, and the third is zero - meaning.

In some cases, zero may be significant and at the end of the number. Rounding, for example, the number 2,540002, we get the number 2,54000, in which all the zeros on the end - significant digits. They point to the deliberate absence of units in the corresponding ranks.

Therefore, if the condition or problem in the table we find the number 4,0 or 0,80, you should consider them as two-digit. Rounding numbers 289,9 to 290, we also get on the end of a meaningful zero.

Significant numbers consist of true and doubtful figures for the approximate number. True digits of this number are counted from its first significant digit to digit with the discharge, which is equal to the category of the first significant digit of the absolute error of this number. The numbers to the left of the correct standing, as faithful, and the first, standing to the right of the faithful, is questionable.

Significant numbers carry information on the measured parameters. Therefore, the number of decimal places must conform measurement accuracy.