This worksheet investigates a simple number recurrence algorithm: if it's odd multiply by 3 then add 1 but if it's even then halve, repeat. Students use the algorithm to complete missing numbers on the sheet.
Very detailed background is given in the guide along with answers.
Great to give students an understandable but unsolved (as yet) problem!
[3x+1 conjecture, Collatz problem, Syracuse problem, Kakutani's problem, Hasse's algorithm, Ulam's problem]