Ah, yes, I see now!
Yes, it seems on the C64, which I suppose is similar to your VIC20, there are ROR, ROL, ASL (arithmetic shift left), but no corresponding ASR ...
Can you spot why teacher failed primary school pupil for answering 5x3=15 in maths test
- Thread starter Blobbenstein
- Start date
OP
OP
Does this mean that you start to calculate when you hear the question "7x5" ?
I don't need to calculate, I immediately know that the result coupled to these numbers is 35, learned that in primary school.
I thought everybody would learn it like that.....
I learned it like that too. Of course, while one is memorizing the multiplication table , one also realizes that it's simply addition.
Indeed, it is simple additions.
When my kids were learning that in primary school, they learned to do e.g. "5x7" by silently mumbling ("ok ... 5x7 ... hmm ... 5 ... 10 ... 15 ... 20 ... 25 ... 30 ... 35 it is!!!!" while counting with their fingers ... and making errors in the counting, maybe 20 % of the time. (Drove me mad, that one, I have to admit)
Needless to say, that I normally asked them multiples of 8 or 9 on purpose, to prove to them the superiority of the "know the tables by heart" method
When my kids were learning that in primary school, they learned to do e.g. "5x7" by silently mumbling ("ok ... 5x7 ... hmm ... 5 ... 10 ... 15 ... 20 ... 25 ... 30 ... 35 it is!!!!" while counting with their fingers ... and making errors in the counting, maybe 20 % of the time. (Drove me mad, that one, I have to admit)
Needless to say, that I normally asked them multiples of 8 or 9 on purpose, to prove to them the superiority of the "know the tables by heart" method
Maybe the old style teaching methods had some merit.
I would always remember the fate of the wives of Henry VIII as someone told me this when I was about 6 years old - divorced, beheaded, died, divorced, beheaded, survived.
I would always remember the fate of the wives of Henry VIII as someone told me this when I was about 6 years old - divorced, beheaded, died, divorced, beheaded, survived.
AeryFairy
Anachronism
That is ridiculous. I used to get told off in class for never showing my workings, but luckily you didn't actually lose points on the exam for it if you got the right answer. The workings were just there to save you a couple of points if the answer was wrong but some of the method was right. But this is worse - the correct workings are right there on the page, the answer is right, and the poor kid is losing points! Jeez.
Mr Crunchy
Forum Legend
There's no way getting around it. You have to know multiplication up to nines to be able to multiply and divide large numbers. But as Blobbenstein pointed out, I have the students do worksheets where they have to solve a puzzle by answering multiplication problems (or whatever we're studying that day). It gives them incentive, and it's self-correcting because if the puzzle solution won't make sense if they get any wrong.
Oddly, some students have expressed to me that they would rather just do a page of rote math problems without the puzzle fun part of it. Go figure.
ledboots
Peace
My sister is a math person, as was my dad. He taught her an easier way to divide when she was quite young, and her teacher accused her of cheating. G tried to show her the quicker way, but she was sent to the principal. That is the only time my dad ever went to the school, in my memory. He was not happy one bit, with his dual engineering/mathematics degrees!
He made me memorize my multiplication tables. Through the 12s. :/
OP
OP
before I was home educated for a few years, the chanting tables, at school, went up to 12......must have been something left from the past...?
AeryFairy
Anachronism
Ha, I can imagine he wouldn't be.
When I was at school, we had to memorise multiplication tables up to the 12s - and this wasn't super long ago (I'm 25), so I wonder if they still do it. We would memorise them, and then ask the teacher to test us when we were confident so she could sign it off. I got told to 'slow down and let the other kids have a chance' when I asked her to test me on all of them in one lesson...
We also had to learn our tables off by heart. I always used to get stuck with the 9s.
I was never very good at maths and hated maths lessons. However, I know how to manage a budget and my money.
I was never very good at maths and hated maths lessons. However, I know how to manage a budget and my money.
ledboots
Peace
9s are easy because the answer adds up to 9. The 8s were my sticking point!We also had to learn our tables off by heart. I always used to get stuck with the 9s.
I was never very good at maths and hated maths lessons. However, I know how to manage a budget and my money.
OP
OP
ledboots
Peace
My dad gave me a ton of little tricks like that because my math skillz are nil.Well, first time I have heard of that !!
AeryFairy
Anachronism
ledboots
Peace
The patience of a saint, he had. I still remember his horror that I was 8 and didn't know my multiplication tables.He was a nice man.
The thing that helped me the most was a song that put the tables to music. I can remember lyrics of songs I haven't heard in decades. A right-brain thing? Idk.
Yes, that is how you can find out if any number can be evenly divided by 9 ... that the sum of all the digits adds up to 9.
Same for 3.
I also learned that again, much later, in my accounting lessons.
When looking for errors in account closing, if the difference you are looking for is divisible by 9, then you have a high possibility that you turned around 2 numbers when transcribing them ... e.g. you put 95678 instead of 96578. The difference is 900, which is divisable by 9. (Of course, if you have made more than 1 error and the differences add up, this won't work any more)
That was, of course, when I learned the "old way" of keeping accounts, on sheets of paper, which was the standard before computers were widely used for such mundane tasks. We learned that possibly to know the history and to appreciate the fact that our school had then just acquired computers and accounting software
