This was a relatively simple puzzle and I got many answers immediately as if this were a buzzer round question. Even my 9 year old, gave me multiple answers in succession, in a bid to get to number 14 in the shortest number of steps. The first one to send me the correct answer was Karan Yadav from Canada, and the first one in the younger generation was Ashwin Godura, followed by Anisha Goyal and Tishyaa Chaudhry. Many other children sent me answers to this one, and congratulations to all of them!
This one does not require a video – here are a few different ways to get to the answer in 8 moves:
458 –> 45 –> 90 –> 9 –> 18 –> 36 –> 72 –> 7 –> 14
458 –> 916 –> 91 –>182 –> 364 –> 728 –> 1456 –> 145 –> 14
Hope you enjoyed this one!
Alok Goyal's Puzzles Page 
Dude, I spent some good time trying to do it in 7 steps or less, until you replied to Ashwin confirming 8 was the answer.
Probably the question for grown ups could be, given a number like 458, how can you determine the shortest path to reducing it to 14 (or whatever number) without doing a brute force search?
good suggestion…do you have an answer?
nope… tried a few hypotheses – had a vague feeling that the answer could be found recursively but didn’t click. I’m not sure there is a answer (in that there is a way to prove shortest path without brute force search)