Balloon Bursting Buttons

Using only these keys on your calculator make each of the target numbers on the balloons. Use the minimum number of key presses.





Brilliant Balloon Busting!

Is it possible to do it using fewer than key presses?


A Maths Lesson Starter Of The Day

Topics: Starter | Arithmetic | Calculator | Place Value | Problem Solving

  • Malcolm P, Dorset
  • A set of real life savers!!
    Keep it up and thank you!
  • Pete Freer, Rotherham
  • Prompted a great deal of enthusiasm and competition to find the quickest way!
  • Joe Murray, Linwood High
  • We did it in 35 moves beat that!
  • Kenny Dyson, Deans Community HS, Livingston
  • We got 34.
  • Russ Skinner, Grant Park High School, Winnipeg, MB, Canada
  • I found an answer for 30 moves
  • Jamie Pascoe, Notton House School
  • I completed this exercise in 28 moves taken screen shot I can email it to you!! :):)
  • BIS Jakarta, Indonesia
  • My clever class did it in 24 buttons!
    Beat that!
  • Mr. B., Essex, UK
  • Can you please provide how you did it in 26 steps ive been trying forever and cant do it in less than 32
  • Year 8 Set 2 Brinsworth Comp, Rotherham
  • As a class we have managed to complete this in 24 moves!
    Can anyone beat that?
  • Transum,
  • Thanks everyone for their feedback. Perhaps we should set some rules here.
    When you first load this starter the target numbers are 16, 24, 97 and 624. If you refresh the page or click the "Change Numbers" button you will get four random target numbers. Let's agree that we are looking for the least number of button presses which achieves the original four target numbers.
    Rather than just the number of button presses you should also record the buttons pressed E.g. 15+1+5+… etc
  • Mr Barnes, Bradford
  • This was a really good starter, I did it with my top set year 7 and they loved it, especially when they realised there were shorter ways than what they had done, it made them determined to find it.
  • Tom, LGS
  • I'm not great at Maths but I did it in 63.
  • Dr Mills, 7M1, Stockport Academy
  • We solved it in 35, and we think we could get it down to 33.
  • Tegan Macintosh,
  • This was a fun activity but we couldn't beat 50 moves.
  • Mrs, Cornwall, Claydon High School
  • My Year 7s have found 16 in 5 moves, 24 in 13 moves, 97 in 14 moves and 624 in 15 moves. Do you know what you the lowest amount of moves is for each number?
  • Year 9, George Abbot
  • We managed to do it in 24 moves. Nice and easy. We await the next challenge.
  • Jack F, Risca
  • Year 8 did it in 48 moves. Hooray.
  • Alex W, Risca
  • Year 9 took 42 moves. Well done to Alex.
  • Shannon And Natasha And Class, Risca
  • We did 40 moves.
  • S Sharples And Year 7, Helston
  • We tried this as a year 7 class and got 44 but will be coming back next lesson as we are sure we can beat it! We loved it.
  • S Sharples Year 10, Helston
  • We got this in 36 moves and would love to know how they got it in 7 because we do not think it is possible.
  • Carmo, Hillsborough Secondary
  • Did it in 41 moves.
  • Carol Lowry, Chapel High School
  • I am disappointed that you can no longer refresh and get the same numbers as classes like to try the same challenge a few times.
    Otherwise great activity.

    [Transum: The Start Again button allows you to do the challenge again with the same numbers]
  • 7A1, Montgomery High School
  • Montgomery High School Blackpool UK Class 7A1 (Mr Gunn's) cracked this in 34 moves. We are awesome!
  • Mr Simon Perry, Orley Farm, Harrow
  • My year 4 Maths set managed to work this out in 34 steps - needless to say I was pretty impressed as I gave them the target of 40!

How did you use this starter? Can you suggest how teachers could present or develop this resource? Do you have any comments? It is always useful to receive feedback and helps make this free resource even more useful for Maths teachers anywhere in the world.
Click here to enter your comments.

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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 such as tablets, iPads or Laptops?  This page was really designed for projection on a whiteboard but if you really want the students to have access to it here is a concise URL for a version of this page without the comments:

However it would be better to assign one of the student interactive activities below.

Laptops In Lessons

Here is the URL which will take them to a calculator workout.

Student Activity

Other broken calculators;
1 and 5 2 and 3 3 and 4 4 and 5 5 and 2 6 keys


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