She's talking about the cardboard tubes from inside kitchen rolls. And I do have a plan for them.
I love my Race to Treasure Island activity, as well as the 'For British Eyes Only' one, that I use for revision (blogged here). The combination locks that I have allow for 3-digit combinations for the codes, which is quite limiting, however.
I had an idea towards the end of last year. What else uses a code? A mobile phone! Could I make something up that I can use a mobile phone's lock code for? Do I have a spare mobile phone? Apparently, no, but my old man did!
So, here is the idea!
I took 7 kitchen roll tubes. I had 6, so I took all the kitchen roll off the one that's currently in use and used that too. I made a (well, an 'as good as can be using kitchen rolls') regular hexagon after covering them in red paper. I taped them all together at the top and bottom, and created a flatter area to attach a mobile phone to. I bought black pipe cleaners to go in the top and sticky-backed velcro to attach the mobile phone to the flatter bit. The result is this:
It looks better in real life... Honest!
So, the lesson...
Write a number of questions. I have created a PowerPoint file to put 7 questions on the board (with an eighth for the code), which automatically continues to a second slide with a 'BOOOOOM' sound after a set amount of time.
I've also created a .notebook file to outline the activity with a link to a bomb countdown timer online, which runs alongside a worksheet with space for 16 questions and a final expression for the code.
You can download these resources on my Maths Resources web page at http://taylorda01.weebly.com/maths-resources.html#revision.
Be careful with the questions, have students round to whole numbers to make it a bit easier if needed, and sit back while kids work individually, in pairs, or small groups in an attempt to save their school from destruction. You could even honour the child with a short ceremony and offer a bar of chocolate as a 'key to the school'.