The following calculators have been owned and used by Hans Sundgren.

Casio MS-10B

- Display: 10 digits, LCD
- No. of keys: 26
- Dual power 1×1.5 V SR54 and solar panel
- Size: 146×102×31 mm
- Weight: 100 g

**2021-01-30**

Hans' favorite calculator is no longer working after 25 years of duty. He wants to replace it with a similar one. He receives this Casio as a birthday gift.

Costs only 99.90 SEK at Clas Ohlson.

- Solar powered
- Large buttons

- Nothing

Ibico® EC-100S

- Display: 8 digits, LCD
- No. of keys: 24
- Dual power 1×1.5 V LR1130 and solar panel
- Size: 125×105×20 mm
- Weight: 78 g

- Not available.

**1995**

During Hans' work when conducting technical training for a large telecom company, the students need to do calculations. For this purpose, calculators are purchased and handed out to the students. Hans also gets one.

- Solar powered
- Large buttons

- Nothing

End of life 2021-01-30

The calculator has been used frequently during 25 years. But in the end it has been subjected to accidents like exposure to water and wine. In addition, it has also been left on a hot stove that melted part of the plastic. Therefore, it is replaced by the Casio MS-10B and is left for recycling.

HP 17B with infrared printer HP 82240B

- Display: 22×2 digits, LCD
- No. of keys: 37
- Memory: 6 kB RAM
- Power consumption: ??? mA
- Battery: 3×1.5 V LR44
- No external power
- Printer connection: IR
- Size: 148×80×15 mm
- Weight: 120 g

**1990**

Hans gets this calculator as part of a work compensation program. He selects the calculator himself and wants an economical type of calculator with possibility to program any problem. This calculator has also an IR-connected printer.

- Very inutitive, easy to program
- Robust design

- The printer has a high power consumption
- xxxx.

End of life 1996-11-27

In 1996 the calculator is stolen when it is stored in a briefcase in the car parked in Djurgården, Stockholm. The printer is left in Västerås.

Commodore SR4148R

- Display: 10 digits, 7-segment, red LED
- No. of keys: 48
- Storage registers: 2
- Power consumption: 400 mA
- Batteries: 3×AA NiCd accumulators
- External power adapter: 6 V DC
- Size: 151×79×36 mm
- Weight: 158 g

- Not available

**August 1977**

When entering the final 4'th year of his engineering studies, calculators were now accepted. So, Hans buys a scientific calculator with R/P functions needed for his last years study of high voltage electrical engineering.

- All possible functions included
- R/P included, which was not the case with other calculators.

- High power consumption, required AC voltage after some time.
- Buttons without "click".

End of life ?

No data.

Sinclair Cambridge

- Display: xxx
- No. of keys: xx
- Power consumption: x mA
- Batteries: x
- External power adapter: xx
- Size: xx×xx×xx mm
- Weight: xxx g

- Not available

**1974 (?)**

Hans reads the magazine "Radio och Television" and sees an ad describing the Sinclair Cambridge calculator from Great Britain. So he orders one.

- A special K-key simplifies constant calculations.
- Small, quite inexpensive.

- Not 100% correct calculations. A correct result of 2.0 could be presented as 1.9999999.
- ???

End of life ?

No data.

Slide rule Hemmi no. 260

- Material: Bamboo coated with celluloid
- Cursor: Metal and glass
- Scales: Front and back
- Size: 320×45×7 mm
- Weight: 125 g

**August 1973**

Calculators are not accepted when Hans starts in high school, studying to be an engineer. So Hans is forced to learn how to use a slide rule.

- Requires no batteries or power supply.
- Gives the user a good mathematical understanding.

- The result is given in only a few decimals and the number of zeros has to be manually "calculated".
- Not suitable for addition and subtraction, even though it is theoretical possible.

Soroban 15 columns

- Material: Plastic
- No. of rods: 15
- No. of beads: 75
- Size: 190×55×15 mm
- Weight: 85 g

- Not available

**May 1972**

Hans is interested in the Japanese soroban, an abacus counting frame, and buys one 1972-05-23 for SEK 19.

- Requires no batteries or power supply.
- Gives a clear visual representation of the calculation.

- Difficult to use for other calculations than addition and subtraction.
- The answer is presented in beads that has to be interpreted to a number.

Brio Abacus 10×10

- Material: Wood and steel
- No. of rods: 10
- No. of beads: 100
- Size: XXX×YYY×XXX mm
- Weight: XX g

- Not available

**1957 (?)**

When Hans is born, his sister is 4,5 years old and her parents buy an abacus for the family.

- Requires no batteries or power supply.
- Gives a clear visual representation of the calculation.

- Can only be used for small calculations, due to only 10 beads per rod.
- The answer is presented in beads that has to be interpreted to a number.