Countdown

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Target

2100

3

6

4

17

15

Use each of the numbers only once with any mathematical operations to make an expression equal to the target.

If you can't make the target exactly, how close can you get to it?

Countdown

A Mathematics Lesson Starter Of The Day


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Topics: Starter | Arithmetic | Mental Methods

  • Mike Moon, Royds School Leeds
  •  
  • I got 173 from 8 x 11 + 5 x 16 + 5
  • Hardip Sahota, Ernesford Grange, Coventry
  •  
  • I did 15 x 14 = 210 then subtract 3 = 207
  • The Best Class Ever (8cd/m2), King Alfred's College OXON
  •  
  • This starter was a nice one to start with for our class. We had two attempts at this one, because somebody shouted out the first answer within 2 seconds(James!!!!!!!!!)
    The sums we had were 49 (which was easy) and 262 (which took longer to do).
    It was a good starter.
  • Chloe Tovell,
  •  
  • I got 226 (one out) by
    8x7=56 then
    16+18x5=170 finally
    56+170=226.
    i really liked this starter of the day and would like to see more like this!
  • Ember, Huddersfield
  •  
  • I had 1008. Numnbers were 1 4 1 18 14. Gives good practice on estimation.20 x 10 x 4 is 1000 take it from there. Finally got there with 18 x 14 x 4 + 1 - 1. It was the last bit that was perplexing. 'Can you do that? questions.
  • 9-5 King's Grove, Crewe
  •  
  • We found this easier to work backwards. We took the 2 away to work with 390 and when from there. 17+8 = 25 +1 = 26 x 15 = 390 +2 = 392.
  • Jericho And Suheera, East Sheen Primary
  •  
  • Answer for 336
    16x18=288
    3x8 = 24
    24 x 2 = 48
    288 + 48 = 336.
  • STEVE EASTOP, MARGATE, KENT.
  •  
  • TARGET: 1573
    NUMBER SELECTION: 2,4,7,13,13
    SOLUTION:
    (13-2) X (7+4) X (13) = 11 X 11 X 13 = 1573!
    I happened to notice at the start that the target figure was indeed divisible by 13 (121 times). It was easy then to get the two 11s needed from the remaining four numbers to multiply by one another to get the 121 necessary to then multiply the other 13 in the five numbers by to get the target!
  • Transum,
  •  
  • Happy Birthday Countdown! This activity is based on a television programme popular in the UK. Sixty nine series have been broadcast since its debut on 2nd November 1982. With over 5,000 episodes, Countdown is one of the longest-running game shows in the world, along with the original French version, Des chiffres et des lettres, which has been running on French television continuously since 1965. [Source Wikipedia].
  • Miss Pocula, All Saints Academy Plymouth
  •  
  • Target 1890 with 1, 7, 8, 10 & 14
    (14+7) x (8+9) x 10
    From Harry Shock 9A1.
  • Jackie, Leicestershire
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  • I got the number 52224 with a lot of trial and improvement. the numbers were 4 8 8 17 and 12. I did 4 times 8 times 8 times 17 times 12 and it worked, this starter was amazing but tricky.
  • East End Primary, Twitter
  •  

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This starter has scored a mean of 3.3 out of 5 based on 469 votes.


Previous Day | This starter is for 2 November | Next Day

 

Answers

15(6 + 4)(17 - 3) = 2100

How many different sulutions do you think there are?

What strategies did you use?

Did you use your head, paper or a calculator?

Or did you use all three?

Could a computer help solve this problem?

Would you improve if you practised solving problems like this?

How could a group of students efficiently work together on a problem like his?

Note to teacher: Doing this activity once with a class helps students develop strategies. It is only when they do this activity a second time that they will have the opportunity to practise those strategies. That is when the learning is consolidated. Click the button above to regenerate another version of this starter from random numbers.



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Laptops In Lessons

Teacher, do your students have access to computers?
Do they have iPads or Laptops in Lessons?

Whether your students each have a TabletPC, a Surface or a Mac, this activity lends itself to eLearning (Engaged Learning).

Laptops In Lessons

Here a concise URL for a version of this page without the comments.

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Here is the URL which will take them to a related student activity.

Transum.org/go/?to=Expression

Student Activity

 


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