'<94t\

"J-_
20 ogzgtz

How to become an
expert calculator ofl the

FAGIT l l3
CONTENTS

I he ,eatures ot taclt Ll-lJ

Only l0 serting keys
Set up the figures with your left hand
turn the cranl. with rhe right. - 3

I'he 3 registers 4

Clearing the registers . 4

The carriage shift key . 5

The tabularor 5

Turning the crank performs the calculation 6

Revolution direction indicator 7

Posirion indicator 7

Decimal point . 8

The machine is loolproof 9

Addition 10

Subtraction tl
I
Multiplicacion 12
-
Short-cut mr.:ltiplication 12

Multiplication involving additioa of products 14

Continuous multiplication 14

Division. 15

Addition and subtract;on of numbers having

10-13 digirs l6
Subtraction below zero 17

Division by multiplication 18

Rule of three t9
Reciprocal vaJues 20

Examples . . .21-24
1. Clearing lever for 5. Clearing lewer for
product register settrng regrster
2. Carriage shift keys 6. Clearing lever for
3. Setting keys
multiplier register
4. Tabulator
7. CranL handle
 :
u
l.a
-
+

4
=

o
U'
Lta

3
4
c
3
o
u.

o
c
H
U'

-
xt

It takes the Facit C1-13 u

only ten setting Leys and a
minimum of auxiliary keys
to master all four rules of U
arithrnetic.
t!
 ,IIE PHYSIOAL LABORATC,. .-
TiJT L!ilIVE,ft8ITY,
ffAIIOHESTER. I&

In addition to the 10-key system, the Facit

C1-13 also offers the following special
features.

qt youl service ...

Overall tens transmission in the product
and multiplier registers, which facilitates
short-cuts, allows immediate readings and
ensures complete reliability; direct division
setting, which saves time and trouble; rapid
ciearing, which increases speed and cuts
down oper ating time.

/ ./ ute atr' Itty' L

/tr
l/
fit< /ea^
//lt/t //yt',t l"/ ""//
lVoI t, 7" plea aV
 Al.l yu d.o is set ap the ligutes
by d.epressing ,be appropliare
setting keys in tbe ord,ei tbe figures appear
in ,he number

only 10 sefiing re'ys

4, /1///
///

Ler us assume that you're going to

//' :i set up the number 1365. First you
set up 1, then 3, 6 and 5 in thar
order. Every time you depress thc
key, the corresponding figure will
appear in the setting register.
 ,ea
'u"'u Here's bout to boost yotn speed
from tbe start:
Set up the ligures
e urith your lell hond
I lurn the cratnk
-with your right
The illustrarion shows which fingers are

used to press down the various setting keys

according to the touch system for which
the machine has been designed.

sutfice to do oll cqlculqtions

By practising this system right from the
start you will very soon Iearn how to cal-
culate speedily and correctly. Like a trained
will be able to operate the
rouch typist you
machine without giving the keyboard as
much as a glance.
This left-hand system leaves the right hand
free for turning and clearing as well as for
making notes.

t
The 5 Registers

Product register Multiplier register

Setting register

The product register The multiplier register

gives the answer when you add, sub .hor s rhe quotient in di"ision. rhe num-
tract or multiply. It also shows thc b.r of ircm. in addirion and rLe muhi
remaindcr whcn you dividc. plicr it multiplication.
The setting register Atithmeticdl tetms are recapiwlated on
immediately records every ligure that pdge 24,
you depress on the setting keys.

Cleoring the Registers

Each of the three registers has irs own clearing lever. Remember
to clear all the registers after each completed computation. This is
done in the following manner:

\Virh your leh land pres down

the leit hand chirins hYo, rDd
vifi your r;sht pres dre orhe.
rwo clcarins lcveb ioseth.r
isiinsr each odrer.
 Corrioge Shilt Keys

The setting mechanism, and with it the set-up numerals in the set-
ting register, are moved step by step to the right or left by means of
the red carriage shift keys. The arrow on the key indicates the
c{irection in which the movement takes place.

Tnc rislt-hand slift key The lef&h.nd shift ley

hoves the nunerils to m6\er rhe fruD nume-
,il( r^v:rd{ rlr.'lcfi

fqbulqtor

tsy a single depression of the tabulator key (to the right on the
keyboard) the setting carrier is brought to the left as far as it will
travel, and this is the usual procedure {or division.

At the srmc time the seruo

.,,mhpr !< cnmnlared wirir
troushts if ;t ionains 1es
llatr 6 d;gis. See illuslra!ion.
furning the cronk perlorms
the colculotion

Once you've set up the figures you can

add, subtract, multiply or divide merely
by turning the crank.
To turn, first pull out the handle
(as indicated by arrow) and keep
it out until the required amount of
turns have been complered.
AII turning movements should be carried
out smoothly and evenly, not jerkily.
Pull;ne out tle handle in the
dne.tion slown by the rrrow

Crank forwards (PositiL,e twn) to add, and

backtoards (negdtioe turn) to sabtract a
number, zohicheuer the calctlation reqairts.
A negath.te turn cancels a positi,tte tum and
oice oersa-permitting instantaneous correc-
tion ol ctanleing mistahes.

After cranking the necessary number of turns the crank must be

returned to its neutral position before the mechanism can be cleared
and a new calculating operation begun.

6
 Revolution Direction lndicqtor

Tlre nurnber of turns made is shown in the multiplier register, "fhis has a turn
direction indicator which shows red for negative coupling. Positive or negative
coupling is determined as soofi as the crank has been turned about half an inch
in thc positive or negative direction, irrespective of whether the turn is completed
in this initial direction or reversed and completed in the opposite direction. A turn
that has been initiated more than an inch must be completed. Negative coupling
is discounted when the register is cleared with the clearing lever.
Thc multiplier mechaaism counts the [umber ol ?ositioe tr.rns-whell. the first and
following turns are positive. It counts the ntrrnber ol negdtfue tans when rhe first
and following turns arc negative.

lJ positioe turns are made raitb a negative coupled rcgister, it counts backwards,
that is to say, it takes off one for each turn. If a start is made with noughts
alone, or the zcro line is passed during calculadon, the complement of the last
nutrber registered in the multiplier register is obtained automatically. (Comple-
ment of 1 : 999999999,)

The revolution direct;on indicato. on rhe

mtrltiplicr resistcr slovins thdt the mrchine a
is rcrdy for nesrtive operation-

Position Indicqtor

The rcd position indicators in the multiplier and product registers are controlled
by the red shift and tabulator keys and thus indicate in which column position
drc machinc operates at the moment.

Product register Multiplier rcgister

Decimql Points

Eranrple of decimal point positioning

in clivision:
33.762
-28.14 : 12

The dccimal indicators arc placed at tle tlrec How divi ion is dor -irl, Lcit Cl .r i' de-
reeisrer apertures and .an be moved sidevays scribed on pase l5.lfter rhe dividcnd(rr.768)
.lons calibrarcd scalcs. llace thc indicator ot i\ bc.', .r up i1 thc p,odu.L r.qi.Ler, plac.
eacl resisrr under the lisure o. poinr on rbe the dccim.l irdicator at 11. Afre. the diyisor
scalethat corresponds to the nunl,er of deci' (i8. rr l.i. b"pn .er uo d noved nqr ro rhe
ett rrd orr'he docimrl poinr lor rl,i nu ber.
N.re
'L,L,he n,nbe n.w ha, rwo nousl,b
rtr.- i', rhrr r'c \r,inq Lp reeisLer ,h-oss
28.1400. 'oThcse nouslB are also .ounted as
.le.:mrlr. Nh!.h hean\ Lhrr Ll,e.e de a in all
'fhe difierence berween 11 and 4 is 7. Thc
mnitiplier .egisrr decnlal indicarors nust
therelore be positiotrcd urdcr 7. lthc rxult of
thc d;vision is 1.2.

Rules for decinzal point

Addition and subtraction. Position thc decimal indicator identically in thc setting
and in the product register. Set up all nurnbers with the same number of decirnals
so that they con,e right rel:tive to the decimal poinr in the setting register.

Mahiplication- The number of decimals in the product register is to bc the same

as the sum of the decimals in the setting up and multiplier registers. Mark the
position of the decimal point in the product register according to rule before
starting calculation.
Diaision. The number of decimals in the multiplier rcgistcr is to be the same as
the differcnce between the nunber of decimals in the product and serting up
registers. You can avoid unnecessary calculating work if you determine the
position of the decimal point and how many decimals are needed in the answer
(quotient) before you start to divide. See also the example at the top of the page.

8
fhe Fqcit Cl-15 is Foolproof

You can nerer carr! oat

ttrto si.multaneous operd,rions
by mi.stake

The machine is so designed that it auto-

matically opposes every manipulation
which might jeopardize the reliability of
the calculation or possibly damage the
mechanism.
Never try to force the machine if it jams.
Jamming indicates that some of the operat-
ing parts have locked-these must be
restored to normal position before you can
resume calcularing. Most of the time you
can unlock the parts by clearing all reg-
isters or setting the handle in its original
position. If these measures fail, you should
get in touch with an authorized, Facit
mechanic.
 Addition

Exam2le: 3478*794+85+8962 - ?

Set up the first four numerals by depressiag the

appropriate keys. Make one forward turn. From
the setting register the.numerals vill then be trans-
ferred to product register,
which will show .

Clear the setting register. Set up the lext numelals,

394, and make a forward turo. The total of the
tvro sets of numerals will theq appear in the prod-
uct fegrsier .

Clear the setting register once more and continue

to add the remainiag items. If you have set up the
figures correctly, the product register will show
the total sum to be

The multiplier register, at the same time, records

that you have added
4 items in all .

Cle.r .ll th. rcsistclr whef, yoo havc conplcted tf,c calculation.

10
 Subtrqction

Erdrn?le: 27 6543-80927 : ?

Set up the ntmerals 276543. Make a forward turn

so as to rransfer the figures from the setting register
to the product register,

Clear the setting register. Set up the lesser number,

80927- Make a backward turn and read off the
tesult . . .

in the product register, This number is the differ-

erce between 276543 ar,d, 8a927.

clear all th€ r€sist€rs wfi€n you haye cotupl€ted th. olctrl.tion.

11
 Multiplicotion

Erdnple: 6943259><2A$ : ?

Set up the greater factor 6943259. Makc 3 for-

ward turns. The multiplier
register now shows .

The product register shows

(6941259 X 3) .

Press down, once on1y, the left-hand carriage shift

t"y (El . This will cause the carriage to move
one step to the left, which is also recorded by the
position indicator. Now make 4 forward turns.
You have now multiplied by 43. Look at the multi-
plier register; it shows .

The product regisrer shows

Press the left-hand shift kev ($f twice (passing

the figure 0 in the multiplier) and make 2 for-
ward turns. You have novr completcd thc multi-
plication and can read the answer (the prodr:ct)
in the product
'"g;.'"..[lEEEEi@]
The setting register shows
the multiplicand .

The multiplier register

records the multiplier .

In this way you are able to check that the correct

nranipulations have been carried out.

Cl.ar all the re8isters wle! you Lave coopleted rhe calcnlarion.

12
 r
I

Multiplicotion i

---l

Short-cul multipllcotlon

If the multiplier contains Iigures of a higher value

than 5, for exairple 8, it saves time to use the
so-called short-cut multiplication method. This is
performed by first moving the handle lrcm its
otiginal position about an inch in the forward
direction. You then bring forth the 8 by making
two backward turns. The multiplier register to the
left of the position indicator will then be filled by
nines. In order to temove these nines you press the
left-hand shift k"y (@ oo"" and make a forward
turn (8 being the saEi as -2*10). By saving all
the turns required for the operation in the normal
way of multiplication you will effecr a time-saving
of up to 40 o/o by using short-cuts.
If, instead, you move t-he handle at once in the
ncgative direction, there will appear to the right
in the multiplier register a red dot which indicates
thar the register is set for minus or negative opera_
tion. If this is the case you n ill have to clear the
multiplier register and the product register and
rePeat the oPeration.

E,!vtlef:!13!=
Set up 758 by pressiag the setting keys. Move the
handle about an inch io the forward direction and
then make a negative turn, The multiplier register
will show a row of nines.
Press the left-hand t and make two
"y lE
forsrard turns so that a fieiit 1 appears in the
multiplier register.
Press (p and make two
the left-hand shift key
backward (negative) turns.
Depress the leit-hand shift key once more @ and
make onc positive turn. The product register now
glves rne answcr. *rr^,r r"l@,
You have completed the operation by 6 turas oI
the handle. Had you multiplied in the ordinary
manner it would have taken 18 turns to get the
same result.
 Multiplicotion

Multiplisqtion involving
oddition ol products

Lt,trnple : 2495X374+4694X38 : t

Thc rrr:ltiplication 2495)1374 is perlormed in the

ordinary manner.

Thc product regisrer now

shows ,

Clcar the sctting and multiplicr registers.

Multiply 4694 by 38.

The product register shows rhc toral amount of thc

two trultiplications

Conlinuous multiplicotion

Examplc: 127 : ?

^l2x31l
The nrultiplication 127XlZ is performed in thc

The product register shows

Clear the setting register. Set up the obtained prod-

uct, 1524, and make a backward turn, causing the
product register to show nothing but noughts,

Clear the multiplier register. Multiply t524 by 311.

The product registcr shows

drc answer

14
 Division

Exarnple: 9955128 t302: ?

Set up the dividend 9955128 by the setting keys,

Press the tabulator @!. Trarsfer the setting to
the product register by a forward turn, then clear
the setting and multiplier registers,
Ser up the divisor 302 by the appropriate keys,
Prcss rhe tabularor (El. tll"t backward turns
until you hear a bell ring and "then one forward
turn. The product register
will now show

Press the right-hand shift key (p once and con-

tinue with backv,.ard turns until the bell rings,
tLen one forward turn.
The product register now
shows

and the multiplier register

Depress the right-hand' shift L"y (p

oo"e -o."
and turn the handle backwards until the bell rings,
then one turfi forward. Now the product register
shows

and the multiplier register

Once again depress the right-hand shift key (p,

crank backwards until the bell rings, then one
forward turn. The prod-
ucr register shows .

and the multiplier register

lfa dipision does not ltotk ort elen
the ntod ct repister utill contain a Again press down the right-hand shift key (p
,"nindc, uhici is smaller tban the
dioisor, and continue backward turns until the bell rings,
rhen a forward turn. The producc register now
Place the decimal point according to
shovs nothing but noughts. The division could be
the insftuctions on ?d*e 8,
completed without leaving a remainder. The answer
(quotient) is recorded
Clear all the tcgisters wheo you
hrve .ompleted the calcul.tion. in the multiplier register .
 Addition qnd Subtroction
of nurnbers hoving 10-15 digits

Exartple: 57$2965782+ t56879623163-5289433223 : ?

Set up as many of the first figures ol the number

as the setting register can hold (9 figr:res). The two
last figures, therefore, have to be left out. Depress
rhc lclt-hand .hiIt key (Q rwice (a" meny timcs
as there arc remaining figures in the numbers).
Nlakc a forward turn.
The product regisrer shows

Clear the sctting rcgister. Now sct up the two

remainirrg figurcs, 82, and makc a forward turn.
The product registcr now shows the completc

Clear thc setting register. Set up the first 9 figures

in thc next number. Prcss thc left-hand shift kcy
(p thrce times and makc a forward rurn. The
producr regisrer now shows

Clear the setting register. Set up the thrce remaining

figurcs, 163, and malcc: forward turn.
The product register now shows the total sum of
thc two added nurabers

Clcar rhc setting register again. Sct up the first 9

figures of thc ncxt number. Press left-Land shifr
kcy (p once ald n:ke a backward turn (sub-
traction).

Clc.rr L\e ,errint r. ci(ter. .ct up thc ,emainin;

figure 3, and nTake one morc backward rurn.
Thc answcr to the entire calculation is now ready
and appears in thc prodr:ct
rcgister .

16
 Subtroction below Zero

Exdm?le: 57-68 +34-136 : ?

Set up thc numLer 57. Make one forward turn.

Clcar the setting rcgisrcr. Set up 68. Make oDe
backward turn. The
producr register now shows

Thc nines to the left in tbe product register show

thar rhc numbcr 89 is negative. The register has
co.rntcd backwards and shows the complemcntary
numbcr to 57 68, which is
-11
(1i+89:100).

Cleer sctting register and set up the rext numbcr,

3,1. Make a forrvard turn.
Product regirer shows

Clear sctting register and set up 136. Makc one

ncgativc turn. Product
rcgister shows
which is a complcmcntary number indicating tJrat
the lcsult is a negative number. To rcad o{f the
answcr, clear the setring register and set uP three
nines imrnediately followed by 887 (the number
found behind thc nines in the product register).
Turn rhc handle twice backward.

'I'he procluct rcgistcr now

shows

-113. The digits to the

Thc answer is left of
the nouehts arc of no importancc.

17
 Division by Multiplicqtion

ExatnPle: 672 128: I

Division can be done in two ways. The most com-

mon method has been described previously.
You can also divide by multiplying the divisor (28)
as many times as required to reach the value of
the dividend (672). By this method you gain the
advantage of being able to read off the answer as
rell .r. dividend and divisor, each in it. appropriate
register.
Set up 28. Press tabulator and continue with
@f
positive turns until the number in the product
register as near as possible approaches the first two
figures of the dividend (67)*. After two forward
turns the figures 55 will appear in the product
register; after three, the figures 84. You therefore
stop after two turns.
Press the right-hand shift key (p and keep turn-
ing the handle forqrard until the factor in thc
product register comes as close as possible ro, or
equals, rhe dividend (672).

Afrer 4 turns rhe product

register shows the dividend

The setting register shows

the divisor

The multiplicr registcr

shows the answer

* The corresponding number of figures of the di-

visor, in this case two.

18
 Rule of three

The rule of three is thc name of a calculating

operation, which may look as followsr

Exam?le: -'r; x435 :

:]5 875
I

First you sct up the largest factor of the dividend

(above the line) preceded by a 0, thus 035875.
The nought is introduccd to keep you frorn exceed-
ing the capacity of the machine. Prcss thc tabu-
l-", lEl. lr will be seen rhar_rhc posirion indi-
c-rtor is now rct ro thc c\trcmc Jcft in thc multipli.r
rcgistcr, and consequently you carry out the mul-
tiplication by the figures 435 in thc order thcy
appear, lrom lelt to rigbt in tbe multiplier. You
therefore multiply first by 4. Then press the rigl,t-
;nd multirlr by r. Prcrs right-
i",i'li! \"r
hand shifc Lcy
@! more and mu)tiply b1 5. Thc
-on.c
multiplier registcr
shows

To the left in thc product

registcr, you now get , .

which is your ploduct.

Clear setting and multiplier registers. Set up 725.

As the first figure of the divisor is grcater than
the first figurc of the dividend one nought is set
up in fronr ol: tLc divi.or. Tlris nill girc one nrore
dccin,al in thc answer.

The nought in front of the number is not necessary.

(sl
and carr)' out the division
il:';"'i:Jil*:;:'
The multiplier register rc
cords the answer

If thc division is uneven, there will be a remainder

which is less than the divisor and it will be shown
in thc product register'.

19
 Reciprocol volues

By the cxpression reciprocal value is'rneant: I

divided by a number or, expressed in fractions:
1

,".b*
t xdnlptc IR :)

This operation can be carried out as an ordinary

division, but thc simplest method is the following:
Ser up 98. Press tabulator (p and turn handle
forward until bell rings, in this particular case,
rwo turns. You will hear the bell at the second
turn. This indicates that you have gone a turn too
rranl ard. thcrefore. you have to make a negarive
rurn. Press the risht-hand shift key
@!f once and
make a forward tum. Thc bell rings and you there-
fore give the handle a backward turn. Press the
riqhr-hand shifr key (!l es.rin and conrinue in
dris manner until the multiplier reeister has been
completely filled with fieures. The answer will
appear io the trultiplicr
rcgister and is

Thc decimal point is positioned according to the

followilg rulc: Put in front of the answer you
received in the multiplier register as many noughts
as there alc units in the original number, in this
casc two noughts. The first of thcse is the unit
nought. The answer is therefore O.O1O2O4O81.

20
 I

Eromple

Summqtlon ol products
For certain J:usiness computations, such as making
up inventory Iists or checking invoices, it is neces-
sary to chech only the grand totals and not the
sub-totals.

Example:
392x6.s9
1,279x3.22
58x2.89
397 X7.93
18x9.27
?

Set up 659 and multiply by 392. Thet cleat the

vith the
setting register only. Repeat this procedure
remaining multiplications.
The product register willshow the sum of the
products. A1l the numbers in the left-hand column
(the numbers you multiply by) are added in the
multiplier register. Our problem now looks like
this:

392x6.59
1,279X3.22
58x2.89
397 Xt.93
78x9.27
2,144 7,802.35

21
Exomple

Computlhg proporiions
Ilxample: 'lotal expenses of 68.75 kronor are to be
proportioned among the folloving four sums:

23.43
294.8A ?

49.6+ )
753.28 )
521.t5 68.7 5

The total of these amounts, 521.15, is divided into

68.75 to obtain a constant, 0.13192, which is used
in the subsequent multiplications. Set up this
constanr and multiply by the first number,23.43
Point off decimal places in the product register and
your answer is 3.09. Don't clear the registers.
Change the figures 23.43 in the multiplier register
into the next number,294.80, by positive or nega-
tive turos. Continue in the same manner with the
two remaining amounts, 49.64 and 153,28.
Finally, check your computations by adding the
answers. Our problem should now look like this:

l).+) 3.09
294.8A 3 8.89

49.64 6.5s
153.28 20.22
521.15 68.75

22
 Eromple

Checklng lnvolces

The following invoice is to be checked:

6,457.73
* 5 olo 322.89
6,780.62

15 o/o discount
-
on 2.500.50 375.08
6,405.54

The amounts of the extra charge and the discouqt

are ateady given, so you begin by multiplying
6,457.73 by 1.05.

The answer is 6,780.62.

Clear setting and multiplier registers The next

mtrltiplication is to be negative. Sel up 2,500.50
and multiply by 15 with negative turns.

The ansver is 6,405.54.

Always make sure that there are the same number

of decimals in both sums.

23
Remember these orithmeticol terms

Tbe f our nrles ol arithrnetic

Addllion
Adderd * Addend : T'otal

Sublrociion
Minuend Subtrabend : Remaind.er
-

Multiplicolion
Mubiplicand. X Multiplier : Prcd.uct

The multiplicand and multiplier are also called factors.

Division
Dioid.eod. t Dilisor : e otient

Dividend and divisor can also be expressed thus:

Diaidend N merdtot'
allO .1fC tllell aalle(l
Di aisor Denominator

lf the nunrerator consists of 2 factors, thc tcrn is rulc ot' tbrec:

Factor X Factor (nun etutor)

( clenomhta,
- or )

24
 look upon your new Focit C1-15 os o
corefully monufoctured instrument . . .

The Facit C1-13 is a precision machine

throughout. It is designed and built to
give perfect service for many years.
Regular attention will guarantee good
and reliable service.
Unlike the majority of calculating
machines the Facit C1-13 is entirely en-
closed and thus protected against dust.
Naturally the mechanism will be subject
ro a certain amount of wear as the oil is
gradually consumed. Like all other
machines it needs cleaning, oiling and
adjusting now and then. This should be
done once a year, preferably by a
service-man approved by the makers.
Obviously the maker's guarantee will be
rendered inoperative if the machine has
been oiled or repaired by unskilled
labour.

FACTT
 l
..ir.

|-

Thanhs for 2oar

interest ! ,

* The time you have put into reading

this little book will be repaid by your Facit

calculator many times over

21.C1.01. Eng. 8 M. 11.59.