MACHINE SHOP CALCULATION - OD1640 - LESSON 1/TASK 2
accuracy in measurement, as for piston, bearing, and valve clearances or
tolerances, and in machining some parts, decimals in the 100ths and 1,000ths
of an inch are commonly used.
As was discussed in task 1, common fractions may be reduced to higher or to
lower terms. Suppose that it becomes desirable to reduce all fractions to a
standard denominator of 10, 100, 1,000, or even 100,000.
Then 1/4 would
These common fractions are now decimal fractions.
But, instead of
simplifying the work, they have complicated it with long, unhandy
denominators. To relieve this complication, a symbol called a decimal point
This decimal point serves to eliminate the denominators.
problem fraction is then presented in its simplest form.
25/100 becomes .25.
The decimal point has now taken the place of the
denominator, which makes it easier to work with.
Definition of Terms
Decimal Point. The point (.) is called the decimal point. It is used
to mark the beginning of the decimal fraction, or to separate it from a
as .025, is a pure decimal. The example reads twenty-five thousandths.
instance, 1.256 is a mixed decimal.
It reads 1 and two hundred fifty-six
Before attempting to read decimals, places should be learned.
A study of
figure 7 on the following page should help. The place in which you write a
decimal point is very important. Each integer (a whole number) in figure 7
is a number 3. Yet, no two of these 3's have like values. The first