1. If I had to take a guess, I'd say... [she's about 35 years old]. 2. It's difficult to say, but I think... [our customers are more satisfied]. 3. Off the top of my head, I'd say... [the company has 500 employees]. (= what I remember/estimate, without checking the actual statistics) 4. It's about... [10 miles away]. 5. It's around... [three hours long]. 6. I wouldn't be surprised if... [Peter asks Jill to marry him]. 7. There's a good chance... [it'll rain tomorrow]. 8. I have a feeling/hunch... [the boss won't be happy about this]. (hunch = an instinctive feeling) 9. I bet... [he'll be late]. 10. Your guess is as good as mine. (= I don't know)