Currently saving up for a DM41L so that I can lend it to select students in the lab. I prefer the landscape form factor, and am ever hopeful of a DM42L, but I know it would be less functional than the DM42 due to the screen size issue. I use that as my main calculator in the lab. The sheer power of the machine was too much to ignore. When I heard about the DM42, I wanted one. It's the part of my brain that was broken for so many years.
The DM15 now goes everywhere with me at all times. I purchased an HP 12c, enjoyed it for a bit but found the lack of scientific functions too limiting, so I sold it. I purchased the Elektronika Soviet calculator because it was cheap, enjoyed it for a bit but was unimpressed with the build quality, so I sold it.
It was as though a switch had been thrown and a whole new skill set immediate became available to me: one I'd struggled with for so long but was so fundamental to my profession. All of a sudden, I could perform complicated mathematics with multiple steps without atithmetic errors. The next day, I looked up RPN properly, switched RealCalc to RPN mode and never looked back. This was my second contemporary introduction to RPN. I'd produced similar things, so we were sharing and comparing. On another occasion, a very intelligent colleague of mine was showing me work he'd done making a PostScript worksheet generator. We discussed the issue of numeracy (lack of it) casually, and she remarked that she used RPN and couldn't use algebraic calculators. I met Prof Crawford a few times through my work. Doing the calculations by hand on the board helped me learn numeracy, at age 29. I'd write on students' exam papers, "you've been casioed" instead of "arithmetic error". "Infernal Casios" and "Gods forsaken Casios" were expressions I'd use when students produced similar numeracy mistakes to what I used to produce because of their over-reliance on calculators and their unshaking trust in the answers they'd give. I discovered, perhaps years too late, that calculators had been holding me back. When I started teaching physics, I would do all calculations on the board by hand. I actually scored very highly in the mathematics modules, but still struggled with numeracy. The mathematics, we quipped, was 'maths without numbers', and I could handle that. I finished school with a grade E in Advanced Level Mathematics, yet still managed to get into university studying physics.Īt university, numeracy was less important. I'm actually pretty strong mathematically, as you might expect from someone with a master's degree in Physics and doctorate work involving computer simulations, but I had little grasp of numeracy. Towards the end of primary school I wouldn't even bother standing to start with. At primary school, times tables were taught thus: all pupils would stand, teacher would ask you a times table, if you got it wrong, you sat down, last standing was the best. I struggled with mathematics at school when I shouldn't have. But, we all got to have our toys!ĭuring my schooling in the 1990s I'd occasionally heard RPN mentioned by my teachers, but only as a passing comment. Of course, that didn’t stop me from ordering a DM42. After re-flowing the solder joint, and a few other “frosty” looking solder joints, the calculator works fine. Meanwhile, I checked the voltage from the two batteries in the HP35c and found a cold solder joint on the positive terminal connector of one of the batteries. I ordered a DM15L and absolutely love it! Then, while looking around at, I found out about SwissMicros. I found out that HP calculators aren’t built to the same mechanical standard that they once were. Wondering if it was a common problem, I searched the Internet. No luck, 3 volts each cell (CR2032) but the low battery indicator persisted and the calculator would shut off after a few seconds. The low battery indicator was showing on the display, so I replaced the batteries. I picked the HP35s which has worked well up until recently. Well, my older brother wanted Dad’s old HP11C, so I decided to get a newer HP scientific calculator. I’ve been using an old HP12c, and a HP11c that was my Dad’s.
0 kommentar(er)
