Is the Fibonacci series essential in Planning Poker?

Our Project Manager has a set of Planning Poker cards he uses for work estimation. These are numbered in the Fibanacci series, 0, 1, 2, 3, 5, 8, 13, …

Sometimes we don’t agree, someone says it is a 13 and someone else says 8. He insists we agree on 8 or 13 when it would be a lot quicker to agree 10 or 11.

You are right, go with 10 or 11.

The whole Fibanacci thing has got blown out of proportion. It is used to a) spread out the answers, b) allow a pack to have small numbers like 1 and 2 but also 60 or 80, c) a bit of fun

There is nothing magical here.

After 2 rounds of voting I normally average anyway.