Memoriad mental addition of ten 10-digit numbers

How does one solve questions like those of memoriad’s mental addition of ten 10-digit numbers?

I searched the forum and it is mostly squaring and multiplication tricks, what about such addition problems?

Does one just brute force it through until they are fast? Or is there tricks to it too?

I searched the web, read Arthur Benjamin’s Secrets of Mental Math book too, but there doesn’t seem to be anything regarding this.

Thank you.


I personally solve that through what you call “brute force”.

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Abacus can Japanese soroban candoo

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Thanks for the reply. Brute forcing adding column by column just feels so slow for me. I guess soroban is the way then (being so proficient to visualize the abacus mentally).

Well, you could take two columns at a time and add double-digit numbers instead… cuts the number of steps in half by adding 5 double digit columns instead of 10 single digit columns.

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