A chuckle for the "Abacus" answer...we had those in grade school, but I also had a couple of those "Slide-Rules," and wish I still had mine from when I was in the Army as it was wide, easy to read, and Yellow in color, but not such a bright shade of Yellow that it hurt your eyes, but I forgot to take it out of a storage unit when I left that trailor court in that city, so that, along with some other things were left there...like a pair of army "Jump Boots."
Also, by the time I got to senior high school, the 9th grade, I had a calculator, and when I was in the army, I had purchased one of those Texas Instruments TI-50's, which had a LED readout, the type of readout they say is dangerous for you to view, but they sure could be easily seen in the dark with that bright display, plus, I wonder how many of you did this, take a number and enter it into the calculator, then turn the calculator upside-down to view the word(s) the number makes? For Example: 710 77345, that is 710(space)77345, upside-down would look like "Shell oil."
Anyway it was one of those programmable calculators.
As far as a computer goes, the first one was a Tandy Color Computer, otherwise known as a COCO Computer, then later on it was a COCO-II, or Color Computer 2 by Tandy, then a HX-1000 I think the model of it was, from Radio Shack, and it was on sale for half price, $300.00, and later I found out why, there weren't any hard drives available for it anymore.
These were all bought new.
Then I went to a computer sale and got a 286 computer
for only $50.00, and it had some name I wasn't aware of, probably a little known company and I can't remember the name of it, but it was full of software that I knew a college student would use and had less than 1 Mb left on the hard drive, and I figure that that's probably one reason it was sold, but I used compression to get around 1/2 of the hard drive space open to me, but I also had removed some of what was on it that I knew I wouldn't use.
Once the people let the general public access the Internet, they had it earlier but mainly for businesses, and they also wanted to set up some sort of way to "police" the Internet or protect it a bit once they opened it up for the public, I had to get a different computer and had to get rid of the ones I didn't need, or couldn't use any longer...and hated to get rid of a perfectly working computer, but they weren't capable of using Windows and used DOS, so I had no need for them anymore.
Interesting to note that the Coco and COCO-II were only 40-columns as far as the display goes, so that was different to get used to, as you'd see 1/2 of the first line on the first line, then 1/2 of the second line on the second line, then you'd see the second half of the first line on the third line and the second half of the second line on the fourth line, Etc.
Oh yah, almost forgot, after the COCO-II I did have a COCO-3 which had an 80-column display.
(Beginning of editing) Oh yes, the COCO, COCO-II and COCO-3 or Color Computer, Color Computer 2 and Color Computer-3 used a cassette tape drive to save and load files. (end of editing)
Have a Great Day,
Bernard