# Broken Calculator

## A Maths Lesson Starter Of The Day

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

16

24

97

624

 0

Congratulations. You did it with 0 button presses.
Can you do it using a smaller number of button presses?

You could also try the Flash version which uses a different type of calculator.

• 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
• George Abbot, Guildford Surrey
•
• 27th Sept We did it in 26 goes. Beat that
• 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
• Peter Freer, Brinsworth Comp Rotherham
•
• Here is the solution for 24 moves from my Y8 class, a team effort.

11 + 5 = CE 11 + 1 + + + + 1 515 + 11 + 1 =
(16) (24) (97) (624)
• George Abbot School, Guildford Surrey
•
• We have also managed to do it in 24 moves. Start with getting the 24 and get the 16 last by using the clear button
• Kerry robb, Brinsworth Rotherham
•
• Alex Robb's mum class 8b did it in 22 moves feeling quite smug.
•
• 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.
• Mr Bracewell, Hanham High, UK
•
• Word - my year 10 bottom set (and proud) got a 27 first go. 'ave sum.
• Mrs Lowry, SPA
•
• We are from Park Academy we did it in 24
•
• We had a go at this in class and no one could figure out how to do it in 24 moves... but i tried it at home and got it!!! 24 moves!! YAY!!!
• L Holmes, Ruislip
•
• Bishop Ramsey Year 11 did this in 21 goes. Well done Chris!!!!
• 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.
• Staines, Surrey
•
• Thanks for the challenge! My year 12 class found a 7 move solution! Beat that!
•
• Calculators are the devil's tools. I remember a time when people relied on intelligence, not coordination! I hate sports!
• Mrs, Cornwall, Claydon High School
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• 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.
• Sydney, Richmond
•
• I did it in 29 moves BEAT THAT.
• Mrs Wright, Pen CP
•
• We did it in 29 too! Well done Y4 at Pen Cp. Yeah.
• Mr Smith, Renfrew High School
•
• My S4 class managed this in 23 moves with the solution below:
15 + 1 + + 5 + + 550 = CE
11 + 1 + + + + 1 =.
• J. Miley, KSSC, Birmingham
•
• Our Year 10's did it in 17-ish!
...but we're very proud!
•
• Our S1 class who are 11/12 years old did it in 21 moves. They were chuffed!
• Mrs. Chetwynd-Knagg, Greengate Junior School
•
• Our Year 4 class did it in 20 steps, very proud!
•
• We are in class 6 and we got it in 16.
• Mrs Fleet, Wanstead High School
•
• We are in year 4 and did it in 7 :).
• Transum,
•
• Please note that all of the comments above refer to the Flash version of this activity which uses a different type of calculator.
• 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
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• 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 John Smith, Lc32
•
• We did it in 15 moves!NOW WHO CAN BEAT THAT!??.
• 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!
• Mrs.Wafaa, DAR AL FIKR
•
• We did it in 10 steps ..... dun dun dunnn UNBEATABLE !!!

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.

If you don't have the time to provide feedback we'd really appreciate it if you could give this page a score! We are constantly improving and adding to these starters so it would be really helpful to know which ones are most useful. Simply click on a button below:

Excellent, I would like to see more like this
Good, achieved the results I required
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Didn't really capture the interest of the students
Not for me! I wouldn't use this type of activity.

This starter has scored a mean of 3.5 out of 5 based on 365 votes.

Previous Day | This starter is for 28 September | Next Day

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.

Christmas Present Ideas

It is often very difficult choosing Christmas presents for family and friends but so here are some seasonal, mathematics-related gifts chosen and recommended by Transum Mathematics.

## Equate board game

Here's a great board game that will give any family with school-aged kids hours of worthwhile fun. Christmas is a time for board games but this one will still be useful at any time of year. Games can be adapted to suit many levels of Mathematical ability.

For Maths tutors working with just one or small groups of pupils this game has proved to be an excellent activity for a tutorial. Deciding on the best moves can spark pertinent discussions about mathematical concepts.

Equate looks a bit like Scrabble--for aspiring mathematicians, that is. Designed by a real mathematician, it works like this: You put down tiles on a board and make points by correctly completing simple equations. Your nine tiles include both numbers and mathematical symbols; you can add on to previous plays both vertically and horizontally. more...

## How Not To Be Wrong

The maths we learn in school can seem like an abstract set of rules, laid down by the ancients and not to be questioned. In fact, Jordan Ellenberg shows us, maths touches on everything we do, and a little mathematical knowledge reveals the hidden structures that lie beneath the world's messy and chaotic surface. In How Not to be Wrong, Ellenberg explores the mathematician's method of analyzing life, from the everyday to the cosmic, showing us which numbers to defend, which ones to ignore, and when to change the equation entirely. Along the way, he explains calculus in a single page, describes Gödel's theorem using only one-syllable words, and reveals how early you actually need to get to the airport.

What more could the inquisitive adult want for Christmas? This book makes a cosy, interesting read in front of the fire on those cold winter evenings. more...

## Graphic Display Calculator

This handheld device and companion software are designed to generate opportunities for classroom exploration and to promote greater understanding of core concepts in the mathematics and science classroom. TI-Nspire technology has been developed through sound classroom research which shows that "linked multiple representation are crucial in development of conceptual understanding and it is feasible only through use of a technology such as TI-Nspire, which provides simultaneous, dynamically linked representations of graphs, equations, data, and verbal explanations, such that a change in one representation is immediately reflected in the others.

For the young people in your life it is a great investment. Bought as a Christmas present but useful for many years to come as the young person turns into an A-level candidate then works their way through university. more...

The analytics show that more and more people are accessing Transum Mathematics via an iPad as it is so portable and responsive. The iPad has so many other uses in addition to solving Transum's puzzles and challenges and it would make an excellent Christmas gift for anyone.

You have to hold iPad Air to believe it. It’s just 7.5 millimeters thin and weighs just one pound. The stunning Retina display sits inside thinner bezels, so all you see is your content. And an incredible amount of power lies inside the sleek enclosure. So you can do so much more. With so much less. more...

## Aristotle's Number Puzzle

It’s a bit of a tradition to give puzzles as Christmas Gifts to nieces and nephews. This puzzle is ideal for the keen puzzle solver who would like a challenge that will continue over the festive period (at least!).

This number puzzle involves nineteen numbers arranged into a hexagon. The goal of the puzzle is to rearrange the numbers so each of the fifteen rows add up to 38. It comes in a wooden style with an antique, aged look.

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## The Story Of Maths [DVD]

The films in this ambitious series offer clear, accessible explanations of important mathematical ideas but are also packed with engaging anecdotes, fascinating biographical details, and pivotal episodes in the lives of the great mathematicians. Engaging, enlightening and entertaining, the series gives viewers new and often surprising insights into the central importance of mathematics, establishing this discipline to be one of humanity s greatest cultural achievements. This DVD contains all four programmes from the BBC series.

Marcus du Sautoy's wonderful programmes make a perfect Christmas gift more...

Click the images above to see all the details of these gift ideas and to buy them online.

 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).

Transum.org/go/?Start=September28

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

Transum.org/go/?to=workout

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

For Students:

For All: