|
The basic rule for deciding how many significant digits there are in a
number is that you count every digit that is actually a known value. The only digits not
counted are zeros whose sole function is holding the decimal place. There are some
examples of finding how many significant digits in various numbers shown in example 20 in
your workbook. Let's look them over. |
418
3.82
|
The first two are pretty straight forward: 418 contains 3 significant
digits; 3.82 contains 3 significant digits also. Notice that the position of the decimal
point is not a factor in determining how many significant digits there are in a number. |
4.002
|
In the next one, 4.002, the zeros are significant digits. They're not
there to hold the decimal point; they are there to show that zeros are known values. |
| 741.80 |
The next one, 741.80, contains 5 significant digits. The zero is a
significant digit. It is not there to hold a decimal point. The zero is there to show
precision. |
| 0.003 |
The leading zeros in the next number (0.003) are holding the decimal point
to show size. They are not significant digits. |
74000
|
The next value (74000) returns us to the dilemma of the zeros. Certainly
the 7 and the 4 are significant digits. Some or all of the zeros might be,
depending on how precisely the value is known. There are at least two and perhaps as many
as five significant digits. Since there is no indication that the zeros represent known
values, just say there are two. |
