A  N A I L  is used to operate the calculator
It fits in the LOOP of the DELETE LEVER

ADDITION and SUBTRACTION are operated in the SAME SLOTS

ADDITION                        with BIG Figures :
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When the figure is in the RED region PULL DOWNWARD
When the figure is in the WHITE region PUSH UPWARD
                with 10s-Carry in the UPPER REGION

SUBTRACTION                   with SMALL Figures :
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When the figure is in the WHITE region PUSH UPWARD
When the figure is in the RED region PULL DOWNWARD
                10s-Carry MUST BE DONE SEPERATELY!
                          ========================

The claim to do "DIVISION" is stretching it ...

BABY CALCULATOR, Chicago, Illinois / USA ( 1930 )

B o d y   S i z e   ( W * D * H )  =   3" * 5" * 3/4"
( =  74 mm * 127 mm * 9 mm  )

Have a look at the SILVER VERSION ...

Have a Look at the HISTORY

impressum:
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© C.HAMANN       http://public.BHT-Berlin.de/hamann        08/12/08