Why doesn't my calculator work ?

[Vagabond]

Yesterday evening my scientific calculator failed. Switched it on....nothing.

 

It has worked perfectly ever since I acquired it (its so long ago I forget whether it was found, or if it was a gift, or I bought it - I am sure though I didn't steal it ! - although it is remotely possible I borrowed it and have long since forgotten who from ) The acquisition (I think) was some time in the 70s or 80s.

 

At first I was nonplussed, but as I sat looking at the dormant instrument, it penetrated my consciousness that these things are battery-driven and I had never changed the batteries since I owned it. .... I wonder...........Looked at the back, found a battery cover, opened it and there were two AA batteries. Went to the battery drawer, extracted two new batteries, fitted them, and YEEESSS , it works, it works

 

Just had a word with Norma, and just like me, she has been using a her scientific calculator for at least 35 years and has never changed the battery.

 

MY calculator is a Casio fx-82A (Norma's is a Casio fx -570)

 

Probably my experience is not unique, but I am a bit gob-smacked by realising I have been using (quite frequently) a bit of equipment for around forty years on the same two AA batteries

 

The old batteries were Casio AAs (obviously made for Casio by somebody) and bear the warning "may explode if set reversely " (anyone ever heard of such an event ?) Modern batteries don't have this warning, so that may be an indication of how ancient the original batteries are - someone must have had a cautious legal adviser in their PR dept.

 

The thought struck me that anyone making batteries that last 40-odd years was gonna die poor !

 

I wonder how long the Duracell AAs I put in last night will last........

[chesters1]

i have a very old general electric ni-cd it did have a serial number showing it was not mass produced ,not been used for years but it still charges up fine

there also seems to be different qualities in what looks to be identical batteries ,my detector came with two energiser 9v batteries obviously supplied to the american maker ,the lasted twice as long as those bought here

Edited September 26, 2015 by chesters1

[Chris Plumb]

My Fx39 is still going strong (though the batteries have been replaced regularly!) I remember buying it for my first semester at Uni - Oct 1978 - cost a small fortune (for then) @ £34. (for comparison my rent was £9 per week!). Folks laugh when they see it now - but it still works fine...

 

C.

[Sportsman]

I remember the first calculator I ever saw. It was in the saloon bar of the Fox and Hounds, but don't ask me exactly when. Mid 70s sound about right?

The guy who produced it was a salesman for something and it had been supplied by his company, more for the novelty value than anything else. It was about the size and weight of a housebrick and had four basic functions.

I remember, we all discussed it and decided that it would never catch on, I mean, who would want something like that?

[Sportsman]

A random thought just struck me. How does a calculator work unless you use the metric system? As an example, in USAand you need the area of a piece of wood, how doe you work out 7 13/16" by 5 7/8" ?

[ayjay]

I don't know the Yank answer, but I would convert the fraction to a decimal - 7.8125 X 5.625 = 43.945.

[Chris Plumb]

My FX39 can do fractions!!

 

Incidently - a quick google suggests the 82a & 570 were released in 85 & 86 - 30 years on one battery is still pretty impressive!

 

C.

[Steve Walker]

My old scientific calculator did fractions too.

 

It also did brackets, so you could have done (7 + 13/16) * (5 + 7/8)

[lutra]

A random thought just struck me. How does a calculator work unless you use the metric system? As an example, in USAand you need the area of a piece of wood, how doe you work out 7 13/16" by 5 7/8" ?

If your still scratching your head Dave, I was taught to think of fractions are a piece of cake. Cut a cake up into the number of pieces your working with and times it by the number of pieces you have.

 

So 13/16 as a decimal would be (1 divided by 16 times 13) 0.8125 and 7/8 would be (1 divided by 8 times 7) 0.875

 

The decimal sum for your piece of wood would be 7.8125 x 5.875 = 45.8984375

[ayjay]

The decimal sum for your piece of wood would be 7.8125 x 5.875 = 45.8984375

That's pretty much what I said, although for some reason I saw (and calculated) 5-5/8 not 5-7/8 .

 

Oh well, can't win them all: (and no-one except me seems to have noticed yet).