This is what comes from forgetting to hit refresh before you submit your post.
Kobal2, words cannot express my rage.
It is not solvable.
Don’t give up!
((50 - 8) * 7 - 5) * (4 - 1)
ETA: Oh, whoops, I ended up forgetting the actual target was supposed to be 866. Damn.
((50 + 4) * 8 + 1) * (7 - 5)
New challenge:
Given: 2, 2, 6, 7, 25, 75
Target: 741
(I just picked numbers by mental randomness. I don’t know what the heuristics are for picking problems that are likely to be solvable, and hadn’t yet seen the problem generator above, so my apologies if this doesn’t work well)
Try with flowers, then ? 
Grmbl, now I come up one short :
(50+4)8(7-5)+1 = 865
I’m going to give up now, if that’s allright ;).
(75+25+6)*7- (2/2) = 741
Target : 203
Given : 2,2,5,7,10,25
25 * (10-2) + 5 - 2 = 203
Working numbers: 5, 5, 8, 10, 75, 100
Target number: 372
5*75 - (8-5) = 372
Working numbers: 2, 3, 5, 10, 50, 100
Target number: 443
Do we not have to use all the given numbers?
(100 + 50) * 3 - 5 - 2
Working numbers: 1, 6, 6, 8, 9, 10
Target number: 788
Arnold’s applet says: “…try to get as close as possible to the target number picked in the second step, using the minimal amount of working numbers in your calculation”.
Oh, I see. Very well then.
8 * (9 + 1) * 10 - 6 - 6
Working numbers: 2, 6, 10, 25, 50, 75
Target number: 216
See post 85 by Indistinguishable
P.S. at the linked webpage I mention above is where I listed a more complete set of rules than what you see in the OP of this thread (which Bryan Ekers has pointed out.)
Also, in the “calculator” at that webpage, you should be able to copy and paste an expression such as 8 * (9 + 1) * 10 - 6 - 6, press the Enter button, and see the result. For those of you (like me) who are getting lazy with their mental arithmetic!
Not in the rules of the UK version (nor, I suspect, the French one). Picking “6 small numbers” is a common ploy in the UK version to make the task harder, used when one contestant believes themselves to be better at solving these problems than the other.
Cool, I did win that one then - thanks!
No - the original French version (according to Arnold) allocates more credit to using more of the numbers, the UK version does not. Although one would think it “best” to use fewer (rather than more) numbers, this does actually make sense when there is a 30-second time limit, as it encourages the contestants to find different ways to get the target when it is trivial.
= ((25 + 75) * 2) + 10 + 6
Since we’re allowing 6 smalls
Numbers are 1, 3, 4, 8, 8, and 9
Target is 333
9 x (8 + 1) x 4 + 8 = 332. Still working on 333.
(9 + 4) x ((8 x 3) + 1) + 8 = 333
1, 2, 3, 7, 50, 100
Target is 913.