[mkirsten]

Can you try calculating 101 * 70 in your head?

[hacker_homie]

I think therefore I am calculator?

[johnisgood]

Very easy to solve, just like it is easy to solve many other ones once you know the tricks.

I recommend this book: https://www.amazon.com/Secrets-Mental-Math-Mathemagicians-Ca...

[jabbywocker]

Completely missing the point on purpose?

[johnisgood]

Elaborate.

[jabbywocker]

you don’t solve it by brute forcing possible solutions until one sticks

[johnisgood]

Yeah, read it in another comment. Why do you think doing calculations in your head is brute-forcing? Many people can do it flawlessly, without even knowing of these "tricks". They just know. Is that brute-force?

[froggit]

I can absolutely try this. Doesn't mean i'll solve it. If i solve it there's no guarantee i'll be correct. Math gets way harder when i don't have a legitimate need to do it. This falls in the "no legit need" so my mind went right to "100 * 70, good enough."

[NetMageSCW]

Or you could do (100 + 1)*70 => 100*70 + 1*70

[ang_cire]

Um, that's really easy to do in your head, there's no carrying or anything? 7,070

7 * 101 = 707 * 10 = 7,070

And computers don't brute-force multiplication either, so I'm not sure how this is relevant to the comment above?

[polotics]

I think it is very relevant, because no brute-forcing is involved in this solution.

[nutjob2]

That's not true, the 'brute force' part is searching for a shortcut that works.

[numpy-thagoras]

The brute force got reduced down to fast heuristics, like Arthur Benjamin's Mathemagics.

[jabbywocker]

It’s almost like you’re proving the point of his reply…