Numbers game is diabolical-help please

[stefan]

i realise that there's a improvement thread, but i was wondering about help for the numbers game.

My word game is quite solid, except for anything over 8 but my numbers game has cost me so many winnable games that i implore you good folks for help.

1 large seems to be the fave, but i tend to go for 2 large......can you end my misery, cheers.

Stef

[Andrew Feist]

Well, I don't know that I'm an expert really, but I tend to go for two large too. I think the things that help the most when I can remember them are (1) you've always got an "extra" large number (with 50 and 100, you've also got 150, etc.); (2) you can use the extra large number to get closer (maybe do 16x50 to get to 800 and then add 75 to get to 875, for instance). I don't always remember these though.

And then there are things that aren't specific to two large, like if you need to 50 x 4 and 3 x 4, then do (50+3) x 4. I have a feeling those just came up again recently.

[Chris Davies]

It's important to learn the 75 times table, up to 75x13 = 975.
You can practice numbers games at www.crosswordtools.com/numbers-game.

[David Williams]

I think two large is probably the most difficult choice. You have potentially four large numbers (x, y, x+y, x-y) and all the combinations of four small numbers to work with. Where to start?

If your aim is no more than to break even I'd go for one large. Options are much more limited, and there's a high chance of a trivial solution.

I've also said before on more than one occasion that there is one simple technique that would gain the average contestant more points than many hours of studying words. If your first stab at a solution starts with, say, 100x6, and there's no obvious way of using the other four numbers to make the rest, remember that you can still use the 6 as a multiplier. (100+n)x6 or (100-n)x6. Missed almost every day.

[Martin Smith]

Agreed - two large numbers apparently has the higher propability of a solution, but they seem easier to find with one large, simply because there aren't as many combinations to work through in 30 seconds. I think the 75 times table, modifying the large number before multiplying (to make 648 or 848 from 100, 8 and 6, for example) and remembering that a number divided by itself is 1 are the most important training tips. I find myself trying to multiply by ten by modifying the large number or creating a new one using two or more small ones, which is probably why I prefer six small. The 5 times table can be useful to get closer to a target as well - 82x5=410 because 41x2=82, for example). Don't worry about the advanced 9 times table Carol often used though - the chance of a 'normal' person finding the solution in 30 seconds that way is negligable.

[Clive Brooker]

Not claiming to be an expert either, but I have some idea.

Once you have the add/subtract before multiplying method ingrained, I would suggest practising the split multiplication, a technique few TV contestants can manage. Once you are proficient at this, a problem where you have, say 25, 6, 5 plus three others and a target in the 700's makes your eyes light up because there are so many ways to manoeuvre towards the target and it's quite easy to explore them. You also find that 25 becomes your friend.

As for 2 from the top, quite often there is an "easy" solution (easy when you spot it) which can make the best numbers player look foolish. So I think it's a good call for a non-specialist who needs to steal the points.

[Charlie Reams]

Once you have the add/subtract before multiplying method ingrained, I would suggest practising the split multiplication, a technique few TV contestants can manage. Once you are proficient at this, a problem where you have, say 25, 6, 5 plus three others and a target in the 700's makes your eyes light up because there are so many ways to manoeuvre towards the target and it's quite easy to explore them. You also find that 25 becomes your friend.

Just to clarify what Clive means by split multiplication:-

Say you have 5, 3, 25 and the target is around 375. So 5x3x25 = 375, but by rearranging the multiplication you can give yourself factors of 3, 5 or 15 (as well as the multiples of 25); e.g. with a 1 in the selection:-

(25x3+1)x5 = 380
(25x5+1)x3 = 378
(25+1)x3x5 = 390

This is a very flexible technique which can often get your near the target even if it's impossible. It can also be generalised to multiple factors, which is often useful in 6 small when the target is near a highly factorisable number like 720.

[Peter Mabey]

It's also worth looking to see if the target is at or near a multiple of one of the small numbers,
As a result of doing non-Countdown number puzzles, I can usually spot factors of any 3-digit number immediately, but don't recommend this as it often leads me to an answer more than 10 away.

[Jon Corby]

Practise. I know this is my stock answer, but meh.

Unlike letters rounds, having a computer telling you the solutions isn't really that much help though.

[Clive Brooker]

When there isn't a totally obvious winning line, frequently there are a number of possible approaches (working up from below, down from above, etc.) and whilst sometimes all of them lead to a solution, sometimes only one does. The key to being consistently successful must be to be able to move calmly through the possibilities, looking at each for just long enough before moving on. Easy enough perhaps when slaughtering the on-screen contestants from your armchair but not when it really matters.

[Junaid Mubeen]

To echo what's already been said, splitting your multiplication is a must. The technique comes into its own in 6 small, when there is no obvious dominant number (especially when there's no 10). In the one large case, chances are you'll be using the large number along with 2 smaller factors to get close to the target and then negotiating the difference with an appropriate split using the 2 smaller ones. This is all waffle until you've applied it in practise. I found the Countdown quiz books very useful for numbers, as they are almost always non-trivial in the sense that they require splitting. Or maybe someone (not me!) could write a list of numbers games that involve basic splitting. Practise is a must.

[stefan]

Thanks for the tips, please continue to add to this thread everybody.

Every little helps

[Gavin Chipper]

I think two large is probably the most difficult choice.

Personally I hate 2 large. I used to wonder if it was just me, but a lot of people seem to find it awkward.

I quite like going for 6 small. Not that I'm an expert at them* but if you can get over the initial panic of "what do I do with these number to make them big?" then you've already got a big advantage over lots of opponents. I don't have any particular techniques apart from the obvious, but my thinking is that you're often quite limited in what you can do to get near the target so the best thing to do is often fairly obvious.

*Actually many moons ago I challenged Jon O'Neill (the numbers God) to a numbers attack on Apterous and although he won, I went for six small every time, and looking at just those game I came out on top. Probably a fluke but it still happened.

[JackHurst]

My advice is to make sure you know the tests to check for factors between 1 and 10. If you can do these in your head quickly, you've got another route to go down in most numbers games to get the target. Don't rely on spotting factors as your main tactic, but having the ability to use it as a secondary or tertiary tactic is a good thing to have in your arsenal.

Somebody did link me to a web page with all the factors tests up to 13, but I dont have the link and more, It was pretty useful.

On the topic of spotting factors, The only test i was aware of for spotting factors of eight was to see if the last 3 digits are divisible by eight, clearly this is useless for numbers in countdown. I came up with another method, which seems to work, but it might be a bit too time consuming for use in countdown numbers rounds, you can give me your opinion on this after you've read the method.

To evaluate if eight is a factor or not, first take the last digit away from the number, to give you two separate numbers:
eg 824 becomes 82 and 4, or 76 becomes 7 and 6
Then double the first number and add it to the second
eg for 824, 82*2=164+4=168, for 76, 7*2=14+6=20
If the resultant number is divisible by eight, then so is the original number.
eg 168=8*21, so 824 has a factor of eight, 20=8*2.5, so 76 does not have a facotr of eight.

Personally, I'd rarely (if ever) use this in a numbers game unless i couldnt spot weather 8 is a factor of the target instantly, but the test looked like it would be easy to carry out.

[Charlie Reams]

My advice is to make sure you know the tests to check for factors between 1 and 10.

If you find yourself relying on taking out the factor of 1 then you may have Mubeen Syndrome and should see your doctor immediately.

To evaluate if eight is a factor or not, first take the last digit away from the number, to give you two separate numbers:
eg 824 becomes 82 and 4, or 76 becomes 7 and 6
Then double the first number and add it to the second
eg for 824, 82*2=164+4=168, for 76, 7*2=14+6=20
If the resultant number is divisible by eight, then so is the original number.
eg 168=8*21, so 824 has a factor of eight, 20=8*2.5, so 76 does not have a facotr of eight.

Personally, I'd rarely (if ever) use this in a numbers game unless i couldnt spot weather 8 is a factor of the target instantly, but the test looked like it would be easy to carry out.

Not a bad idea, but then you have to do the division by 8 separately. You might as well just keep dividing by 2 and see how far you can get, which is pretty easy, and gives you the relevant factors directly.

[JackHurst]

My advice is to make sure you know the tests to check for factors between 1 and 10.

If you find yourself relying on taking out the factor of 1 then you may have Mubeen Syndrome and should see your doctor immediately.

Ha