When did the Old Kingdom and the Middle Kingdom begin in Egypt, and how were these two periods similar?

i need this answer asap

I think it happened during the First Intermediate Period of the Old Kingdom. During this time there was a decline on the government. This event paves way to the Thebes Dynasty to rise and unite the Upper and the Lower Kingdom

The similarity of those eras would be prosperity. Egypt was prosperous during the Old Kingdom, that is why it does not barter with other city states because the country has more than enough for its people. However, during the Middle kingdom, the pharoahs wanted to make Egypt more prosperous than it was. They opened Egypt to inter city trades and strengthened their relationship with their allies.