4. ‘The prime number few.’
Here ‘prime’ is being used as a noun representing ‘prime people,’ the same way ‘the old’ represented ‘old people’ up above. ‘Number’ is our verb, meaning ‘amount to.’ But our brains are so used to seeing ‘prime number’ as a noun that it’s hard to separate the two on first glance. In other words: ‘There are few prime people around.’ (The same goes for linguists.)