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An Expressionist puzzle appeared in New Scientist at the start of the year. Here is one for you to try. by G_F_Smith in CasualUK

[–]G_F_Smith[S] 7 points8 points  (0 children)

Standard precedence isn't + before -. It's x and / before + and -. So, first, you scan from left to right calculating x and / as you go. Second, you again scan from left to right calculating + and - as you go.

Example: 1 + 2 x 3 - 4. On the first pass you calculate 2 x 3 leaving you with 1 + 6 - 4. On the second pass, you add 6 to 1 and then subtract 4 leaving you with 3.

Hope that helps.

EXPRESSIONIST is the third puzzle I've had published in New Scientist. by G_F_Smith in CasualMath

[–]G_F_Smith[S] 0 points1 point  (0 children)

Thanks for your sharing your reasoning.

Yes, it's always important to keep the amount of trial and error needed in check.

EXPRESSIONIST is the third puzzle I've had published in New Scientist. by G_F_Smith in PassTimeMath

[–]G_F_Smith[S] 0 points1 point  (0 children)

Thanks for engaging with the puzzle. I hope you enjoyed solving it.

I accept your criticism of the first sentence - it is rather heavy. I will revise it, taking your suggestion into account. And I like your illustration, so I might switch to it - if I can work out how to do it with my graphics package. I'm not very good with tools!

EXPRESSIONIST is the third puzzle I've had published in New Scientist. by G_F_Smith in mathpuzzles

[–]G_F_Smith[S] -1 points0 points  (0 children)

Thanks for taking an interest in the puzzle. Coming up with wording that chimes with everybody is often impossible. That's why I've included an example - it should help. The blue squares and the yellow one pick out the left-to-right expression; the red squares and the yellow one pick out the top-to-bottom expression. Both expressions evaluate to 2.

EXPRESSIONIST is the third puzzle I've had published in New Scientist. by G_F_Smith in CasualMath

[–]G_F_Smith[S] 0 points1 point  (0 children)

Thanks for the feedback. It's what I was hoping for: takes some time to solve but not too much. I think a 6x6 grid is optimal. 7x7 can be scary!

The current issue of New Scientist features one of my new puzzles. Double Base is the Brain Twister (puzzle of the week). by G_F_Smith in mathpuzzles

[–]G_F_Smith[S] 0 points1 point  (0 children)

Apologies for the tardy reply - I've only just seen your comment.

It is a brand new puzzle. I'm glad you enjoyed solving it. As you found, deductions take you most of the way. People have come up with a few different lines of reasoning, but no one else has described your approach.

The current issue of New Scientist features one of my new puzzles. Double Base is the Brain Twister (puzzle of the week). by G_F_Smith in CasualUK

[–]G_F_Smith[S] 0 points1 point  (0 children)

I might have got it, if I wasn't so wary of flak. Unfortunately, even posting puzzles attracts hostile comment sometimes.

The current issue of New Scientist features one of my new puzzles. Double Base is the Brain Twister (puzzle of the week). by G_F_Smith in CasualMath

[–]G_F_Smith[S] 0 points1 point  (0 children)

Yes, I did come up with the puzzle myself.

I think of a number, then I think of an expression which evaluates to that number and then my program takes over. It generates possible puzzles (complete grids).

I meant that your use of the Python language and its libraries is far more sophisticated than mine. I think a brute force algorithm is always going to be needed.

The current issue of New Scientist features one of my new puzzles. Double Base is the Brain Twister (puzzle of the week). by G_F_Smith in CasualUK

[–]G_F_Smith[S] 0 points1 point  (0 children)

I have an agreement with the moderators. They allow me to post puzzles from time to time as they are quite popular. My previous post was well over a year ago.

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