I know this is an idea that has been around for a while, but as a relatively new teacher, it is the first time I have got round to actually doing it this way. I have done the challenge in class before, but this term I am opening it up to the whole school!
For those who don't know, the Four 4s challenge asks students to use the digit 4 four times along with any mathematical operations to make the numbers 1 to 100. They can combine the digits to make 44, and can use any operations they can think of, including factorials, powers and roots (as long as they make the power using 4's!)
I have put the display in the main maths corridor, which is in a fairly central location in the school. Rather than have students write their own answers on the display, and to allow the activity to continue when I am not there to check and write up immediately, I have come up with a system where they submit their solutions on a named slip, which they hand in to be checked. If correct, I will then add their solution and name to the display for everyone to see.
To add another edge to the problem, I will also be allowing them to submit "better" solutions for numbers which have already been solved. By better, I mean more efficient, which will be measured by the number of key presses on a calculator it takes to input the calculation.
I am hoping that the location and input method will get the whole school involved in the problem, from Year 7 to A-Level. I am also going to award prizes for completing "random" numbers, which I have pre-chosen as winning numbers, but have not told them which ones they are.
I put up the display on the last afternoon of school, after the students left, before Christmas, and I am looking forward to getting underway with finding them all!
I am a maths teacher looking to share good ideas for use in the classroom, with a current interest in integrating educational research into my practice.