TM 5-6640-212-14
down until cleared by the operator. The nonrepeat key is
Set on keyboard 45
Make one forward turn of
located above the repeat key. When the nonrepeat key
operating crank.
is depressed, the keyboard clears after each turn of the
Set on keyboard 15
Make one backward turn of
operating crank.
operating crank.
In lower dials 30
Answer.
NOTE
(3) Adding and subtracting with repeat key. )
The repeat key must be depressed
Addition and subtraction can be done exactly as above
when the machine is used for
with the repeat key depressed. When this is done, the
multiplication and division.
number added or subtracted remains on the keyboard
(7) Keyboard clear key. This key is marked O and
after the turn of the operating crank. This saves time
is located at the lower right corner on the face of the
when adding and subtracting numbers which have one or
machine. Depressing the key clears the entire keyboard.
more digits the same, For example, to add 3 to 47
At the bottom of each row of keys there is a zero clear
depress the repeat key, clear the machine, and process
key. Depressing any of these keys clears the keys in
as follows:
that column.
Set on keyboard 47
Make a forward turn of
(8) Carriage shift lever. This lever is located at the
operating crank.
left front of the machine. By half a turn of this lever, the
Change keyboard to 43
Make a forward turn of
carriage may be shifted to the right or left as desired.
operating crank.
When the carriage is shifted, the operating crank must
Change keyboard to 40
Make a backward turn of
be in the upright position.
operating crank.
c. Clearing Machine. The operator should always
In lower dials 50
Answer.
remember to clear the entire machine before starting any
e. Multiplying Whole Numbers. Multiplication is
new work. To clear the keyboard, depress the keyboard
done by setting one figure usually the larger, on the
clear key. For upper dials clearance, make a complete
keyboard and writing the other figure in the upper dials
forward turn of the clear-out crank; for lower dials
with the operating crank. The repeat key must be
clearance, make a complete backward turn of the clear-
depressed when the machine is used for multiplication.
out crank.
For example, to multiply 12 by 12.
NOTE
(1) Depress the repeat key, Clear the machine.
The operating crank must be in
(2) With the carriage in position 1, set 12 on the
upright, or neutral, position when
extreme right of the keyboard. Turn the operating crank
clearing.
forward 2 turns. If too large a number is turned into one
d. Adding and Subtracting Whole Numbers.
of the upper dials, it can easily be corrected. Simply
Addition and subtraction can be done with the carriage in
position the carriage so the carriage position arrow points
any position, but it is suggested that the carriage be
to the dial showing the incorrect number and turn the
placed in position 1, that is, as far to the left as possible.
operating crank backward until the correct number
The most rapid and efficient way to add and subtract is
appears. If the incorrect number is too small, turn the
with the nonrepeat key depressed so that the numbers
crank forward until it is correct.
automatically clear from the keyboard.
(3) With the carriage shift lever, shift the carriage
(1) Adding with nonrepeat key. To add 12, 23, and
one place to the right. Turn the operating crank forward
34, depress the nonrepeat key. Clear the machine.
one turn.
Set on keyboard 12
Make one forward turn of
(4) The result should be:
operating crank.
Upper dials
12
Set on keyboard 23
Make one forward turn of
Keyboard
12
operating crank.
Lower dials
144
Set on keyboard 34
Make one forward turn of
Answer
operating crank.
If the correct numbers show in the upper dials and
In lower dials 69
Total.
keyboard, the answer cannot be incorrect.
(2) Subtracting with nonrepeat key. To subtract 15
f. Multiplying Whole Numbers With Constant
from 45 depress the nonrepeat key. Clear the machine.
Multiplier. The above explanation of correcting the
upper dials naturally leads to the problem of having to
multiply the same number by several dif
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