Is solving one task (of 10) of Memoriad's Addition Tasks, less than 1 minute, a good result?

@Kinma, @Nodas, @flou, @albinoblanke, @Mayarra, I want you all to do one task addition in Memoriad to see your level guys!

Only competing against the best results of the best calculators give me will to train, so please answer back my request.


Less than 1 minute is a good result.

But I have seen with my own eyes the world record holder Mrs. Lee, when she did less than 10 seconds for such a task. (and 10 tasks in 100 seconds)
Her absolute best for such a task, is around 7 or 8 seconds.

I rarely train such additions, even before competitions.

Abacus and soroban users can be 200% or 300% faster in this category.


Thanks for replying @Nodas!

Hi Benjamin! You have done a pretty decent job!
I didn’t train for a while, 4 weeks after last time I talked with you, I caught H1N1 flu, and spent a month in hospital, then I was treated for my insomnia and bipolar, I didn’t come home until Nov 7.
But anyway I will still offer some clue. lol
I don’t like to split the numbers when I’m doing Addition in Memoriad, back to August I finished 10 tasks in 190 seconds or so, if I recalled correctly.
Due to lack of training my speed dropped quite a lot, especially when processing big numbers, my grade doing Memoraid Addition now will probably be really, really poor.
So I choose to do 3*3 multiplication, although it is still pretty bad and within 1 error, but at least not that heartbreaking. lol I’m so sorry

Video of myself doing this:

I might restart training next in December. I will inform you my progression later. Sorry again for disappoint you…lol

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Thanks for replying.

Bipolar? That’s explain your insomnia!

Well done in multiplications!

Is there any technique behind it ?

No, just the basic vertical method.

When I realized that there are other advanced methods like soroban or criss cross, It was a little bit too late, and I’m not willing to adopt a new system, since vertical method works well for me.

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That’s pretty good Benjamin, you are getting really fast. I haven’t done any addition in a long time, I’ve never done that type of addition either. I guess I have to check out Memoriad.

Can you explain how you do it? Because I’ve been trying to find some videos about vertical method (I’ve never learned it, they didn’t teach us that at school) but can’t find one with large multiplications, only 2 by 2 and 3 by 2.

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Thanks for the reply, Johnny, eu estoy agradecido, ele meu adiçao è muito bom desta vez!

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Amazing, your boy is very fast and accurate, an authentical wizard!

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In every video I’ve come across of vertical method they go from right to left but you go from left to right.

When I calculate 338x886 I need to calculate 300x886+30×886 first and then I know that the first digit is a 2 but you know instantly, in less than a second that the first digit is 2, how?

How can you calculate 330×886 in less than a second but then take 2-4 more seconds to calculate 8x886?

I can’t find a video that explains your way of calculating, could you please explain it? I think I am missing something obvious but I don’t know what.

Voce e rapido. Eu nao falo mais portugues, este é meu melhor portugues, haha:)

Esta “isto” ou “este”? Eu nao sei! X)

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Your son is pretty amazing! Congratulations!

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It’s doesn’t really matter whether from left or right to start. Just little change can tackle this problem.

It’s tidy for people who calculate by pen. But for mental calculation using vertical method, i think it’s better (at least for me) to write it from left to right, the advantages it brings are more than disadvantages.

I think this picture could tell you something.
In an n*n multiplication(here we only consider about the 2n answer, no 2n-1), the first digits is easy to determine(sometimes need to estimate, whether +1 or not) and the second digits to the n-1th digits is the most difficult part, and the n+1th digits to 2nth digits are follow by the nth digit.
(Wish you could understand what I mean. My English don’t allow me to explain complex concept. )

It’s 330x886 and 038x886.
My speed is constant(approximately), most of the time it won’t vary dramatically.
2-4 seconds more seconds is a little bit too long. Most of the time I don’t even need that long to finish the task, including the time writing it done.

It’s an simple method. I think you would gradually understand after you start using it!

I still don’t understand. The reason the cross method is so populair is because it is essentially single digit multiplications and adding the answers up. For example, 215×347 is (2×3)+(2×4+3×1)+(2×7+3×5+1×4)+(1×7+4×5)+(7×5), which is much easier than the basic method from elementary school. With the cross method you can calculate the first digit instantly too because you have to deal with very small calculations like 2x3 and 2x4+3x1.

I have to calculate 200x347= 69,400, 10x347=3470, 5x347= 1735.

I cannot instantly know the first digit because I cannot calculate 200x347 and 10x347 and then add up 69,400 + 3470 that fast, I need 1-2 seconds.

How do you determine the first digit of 478x896? That is what I need to know.

Calculate the 478x8, and the first digit is obvious. (Whether +1 or not depends on 478x9, if didn’t +1 just delete the first digits and +1, and so on.) That’s how it work.

I 'm a little tired of answering this type of questions, I think you can figure them out yourself later.

I am actually terrible at doing additions like these ones fast haha, I took around 100s average on all 10. While I love math and finding ways to do it easier, I am not good at doing it speeding it up :slight_smile:

Congratz on your sub minute time :slight_smile:

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Ah, I understand. You calculate 478x8=3824, I calculate 478x800=382,400. To me 3824 is completely different from 382,400. I never learned to carry over digits and leave out zero’s. I remember other kids at my school using this method, I didn’t understand what they were doing back then. I do now. My girlfriend used the vertical method too in school, she said it is sort of a short cut and easier than the basic method, the basic method is what I do. I guess I am too used to the basic method because the vertical method is too strange for me to do, without the zero’s I get confused.


You must have an extraordinary working memory I think.