This is a relatively simple arithmetic puzzle, that I found interesting to do with my 9 year old. I picked this up from Mathematical Circles. Here is the puzzle:
You begin with the number 458. You are only allowed two operations, each of which can be repeated any number of times:
– You can multiply the number by 2
– Remove the last digit, i.e. the one in the unit’s place (e.g. 8 in the number 458)
Your task is to get to the number 14, beginning with 458. Do this in the minimum number of steps.
Happy crunching, and as always, e-mail your answers directly to me at email@example.com