Answer:
5,000
Step-by-step explanation:
Because 5 is in the thousands place and it is asking his neighbor 0 for help and since 0 is it a 5 or above he can't help 5 so 5 has to stay at 5,000 and can't go to 6.
I'm sorry I was late but I think this could still help you I hope have a great day:)
