Numbers games

JaneFairfax · 2009-03-07 04:18:26

Another game on the game show Countdown is the numbers game. In this game, contestants have to get a randomly generated number (called the target number) from six numbers by addition, subtraction, multiplication and/or division. For example, the target number might be 350 and the six numbers to play with might be 25, 10, 1, 1, 3, 5. One way to do it is: 25 + 1 + 1 + 3 + 5 = 35; 35 × 10 = 350. Another way is: 10 + 5 − 1 = 14; 25 × 14 = 350. Yet another way: 25 × 3 = 75; 75 − 5 = 70; 10 ∕ (1+1) = 5; 70 × 5 = 350. No doubt there are plenty of other ways.

Note that

(i) You dont have to use all of the six numbers. In the second solution above, the 3 and one of the 1s are not used.

(ii) You cannot use a number more times than it appears. In the example above, the 25, 10, 3 and 5 appear once each, so each of them can only be used at most once; the 1 appears twice, so you can use it none, once or twice, but not more than twice.

(iii) If you use division, the quotient must always be a whole number.

Okay, here is a simple game to start off.

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lightning · 2009-03-07 04:23:27

Can you make mumbers bigger like for example;

1 and 8

can you use it as 18 or 81?

mathsyperson · 2009-03-07 05:12:57

Assuming we're playing by Countdown rules, then no, sticking numbers together like that isn't allowed.

JaneFairfax · 2009-03-07 05:28:17

Nice work, Mathsy.

@lightning: The rules say you can only use addition, subtraction, multiplication, division. Can you make 18 or 81 from 1 and 8 using only these operations? Well, you cant. So the asnwer to your question is no.

Pay attention also to the special rule about division: if you use division, you must always get a whole-number result. I know this because someone I know once asked this question during his Countdown audition. He asked Mark Nyman (the person in charge of contestants and auditions in those days) whether fractions were allowed on the numbers games, and the answer was no.

Last edited by JaneFairfax (2009-03-08 00:52:20)

lightning · 2009-03-07 05:38:39

ok thanks because i added 75 to 3 making 78 x 10 = 780 / 8 = making a decimal

JaneFairfax · 2009-03-07 05:57:37

Next one is a bit more challenging.

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Jai Ganesh · 2009-03-07 17:06:23

JaneFairfax · 2009-03-07 22:49:00

Yes, thats the way to do it!

JaneFairfax · 2009-03-08 05:20:29

Now try this!

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This game actually turned up in an edition of Countdown aired in 1997

it was actually solved by one of the contestants on that show, within the 30-second time limit!!

Well, if he could do it, no reason why you cant.

mathgamesfun · 2009-03-12 06:43:23

My answer:

JaneFairfax · 2009-03-12 06:47:04

How did you get 175?

lightning · 2009-03-12 06:50:19

952

+ 25 50 75 100

256 x 3 = 768

Is that close enough?

JaneFairfax · 2009-03-12 07:36:55

Oh well. I dont think anyone is going to get #3, so here it is.

Last edited by JaneFairfax (2009-03-12 08:21:59)

Kurre · 2009-03-12 08:01:19

my first thought on the first one was 75*10/(8-6)+3

Jai Ganesh · 2009-03-12 09:42:54

I don't think I could've solve that one.
A tough one, but a challenge, nevertheless.
I was getting all answers pretty close to 952, but the solution was elusive!

Devantè · 2009-03-12 19:13:53

There's a countdown numbers game downloadable free online somewhere... gotten some really tricky ones from that. I like to pick 6 numbers from the top, makes the arithmetic somewhat harder.

mathgamesfun · 2009-03-13 03:33:02

You can play the coutdown numbers game online at www.dilan4.com

mathsyperson · 2009-03-13 06:33:50

The first game I got from that link was:

100 50 8 7 5 10
731

The only solution I can see to it is fairly complicated, so have fun!

mathgamesfun · 2009-03-13 07:35:34

How is this?

sony · 2009-03-16 20:38:14

Nice game. Good training for the brain:}

lightning · 2009-03-21 00:03:12

Ohh, this is so hard. NVM I don't want to play. Sorry!

JaneFairfax · 2009-03-21 01:47:52

Okay, this was most probably what James Martins thought processes were when he did that legendary numbers game.

First he noticed that

Since 9 = 3×3, he experimented with splitting up the 9 that way.

He made the 318 using the 100, 6 and 3 as we see in the YouTube clip. Now he just needed to make another 3 and a 2 from 25, 50, 75. In a situation such as this, the distributive law of arithmetic is your friend.

Jamess skill lay in not only knowing what to do but being able to do it fast enough in 30 seconds as well. In fact, he didnt even need to work out 318×75 at all. Much better to let Carol Vorderman do it instead.

Math Is Fun Forum

#1 2009-03-07 04:18:26

Numbers games

#2 2009-03-07 04:23:27

Re: Numbers games

#3 2009-03-07 05:12:57

Re: Numbers games

#4 2009-03-07 05:28:17

Re: Numbers games

#5 2009-03-07 05:38:39

Re: Numbers games

#6 2009-03-07 05:57:37

Re: Numbers games

#7 2009-03-07 17:06:23

Re: Numbers games

#8 2009-03-07 22:49:00

Re: Numbers games

#9 2009-03-08 05:20:29

Re: Numbers games

#10 2009-03-12 06:43:23

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#11 2009-03-12 06:47:04

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#12 2009-03-12 06:50:19

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#13 2009-03-12 07:36:55

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#14 2009-03-12 08:01:19

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#15 2009-03-12 09:42:54

Re: Numbers games

#16 2009-03-12 19:13:53

Re: Numbers games

#17 2009-03-13 03:33:02

Re: Numbers games

#18 2009-03-13 06:33:50

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#19 2009-03-13 07:35:34

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#20 2009-03-16 20:38:14

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#21 2009-03-21 00:03:12

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#22 2009-03-21 01:47:52

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