Fifty or a hundred digits sounds impossible until you realize it’s nothing new, it’s Day 9’s number-word dictionary plus Day 6’s expanded palace, run at scale. Chunk the digit string into pairs, convert each pair to its picture-word, and place the words along a long palace route, several per stop if needed.
The only real challenge at this length is staying organized: use consistent “landmark” stops every ten digits (a doorway, a corner) so if you lose your place, you can jump back to the nearest landmark instead of restarting from digit one. This is exactly how memory athletes handle hundred-plus digit numbers in competition.
Work through a longer number below, chunked and chained the same way.