A few months ago I created these Four 4s posters from 1-100. If you're not familiar, these are problems where you can use exactly four 4s to get a certain number. Operations such as plus, minus, multiplication, division, exponents, square roots, and factorial can be used. And of course parenthesis. Be careful that you only use the number 4. For example, don't use a 2 as an exponent. And be careful that you use exactly four 4s....not three 4s or five 4s.
I wanted something for the early-finish students. When a student finishes their classwork early, he can try to figure out one of the open numbers. As a student would determine one of the numbers, she would show it to me for confirmation, write her solution next to the number and sign her name.
And yes, you can find solutions on line and I addressed this right away with the students. You can find one such website here. I told the students that we wouldn't be looking these things up online, we wanted to see what we could do on our own. As you can see from the image below, I believe the students are complying with our agreement.
Some of my students are really into this. One student has 10 of the numbers and another student has 12 of them. Keep in mind that I have over 100 students, so these two students are really going to town. When I first posted the numbers and explained how it works, a few students were so excited, with one student saying, "I WILL get my name on that poster!".