The Collatz conjecture is a famous unsolved problem in mathematics, sometimes call the 3n + 1 problem. This is a simple program that generates Collatz sequences for any positive whole number that the user inputs. The question here was, "Can I code a program that will let me see different sequences for different starting numbers? Though it is fun and good practice to do it with a marker and whiteboard, I really need something faster than my brain." The main parts of this program are loops, number variables, lists and conditionals. As a bonus, you can use this to teach how to use the MOD operator.* Everything in here is doable according to the Ontario 1 - 8 Math curriculum's coding strand for grades 5 and up. I would encourage teachers to have their students try this out rather than just giving them this program. You could/should start your students out using pseudo-coding depending on their experiences and abilities. *MOD operators divide a whole number by a divisor of your choosing and return the whole number remainder of that operation. 9 MOD(2) returns a 1 because it is an odd number. 8 MOD(2) returns a 0 because it is even. There are more MOD(x) things you can do with number sequences. Stay tuned. If you would like to know more about this problem and how rich it is to use in class, there will be a video soon about it on the Mathomance YouTube channel: https://www.youtube.com/channel/UCH_2-wVHUNZ50JPIbdgKx2w
