Anyone who teaches in New York City Public Schools knows that from time to time you get asked to cover a class when a teacher is absent. Personally, despite the hectic nature that is a school day, I typically enjoy these coverages mainly because I get to meet and interact with lots of students that I either don’t know or don’t teach.

Lots of times, there is an absentee lesson plan, but many times there’s not. What’s the result then? Me in front of a class of 30 adolescents for 45 minutes with nothing to offer them. Last year I realized that I was tired of this. Here is an attempted remedy.

I’m want to compile mathematics tasks meant engage students that I’ve never met before. Since I teach high school, I will assume nothing about prior knowledge or motivation besides the students being in grades 9-12. The tasks should be *highly* *accessible*. Also, in terms of materials, I’ll have nothing but a whiteboard and/or Smartboard at my disposal. I love mathematics, but since I’m not the best at coming up with stuff on the spot, this page will be a necessary resource for me. It’ll be updated regularly whenever I come across worthwhile ideas.

- The Four 4’s. Express the numbers 1-20 using only four 4’s and any set of operations. Additional challenge: express the numbers 21-???)
- Similar to The Four 4’s: Using each of the digits 1, 2, 3, and 4, once and only once, with the basic rules of arithmetic (+, –, x , ÷, and parentheses), express all of the integers from 1 to 25. Source.
- Sprouts | A fun game that involves nothing but a pencil and paper. Get’s deep.
- The password riddle | Connect the computer to Smartboard to show video. There are loads more like this from Ted-Ed.
- What comes next? O, T, T, F, F, S, … | A clever little sequence.
- Which One Doesn’t Belong? (Numbers and Shapes) | These give every student an opportunity to show off their mathematical perspective.
- Add seven subtract one | A great problem to promote numeracy.
- Are there any operations that make the equation 5 5 5 5 = 19 true? (Source)
- Variable analysis game.
- Find as many patterns as you can in Pascal’s Triangle.
- Various problems from the Man Who Counted (book) by Malba Tahan

bp