Another way is narrow down if result No. is very large.
For example, No. 100K result not exists.
Then look for No. 90K; If not found, then 80K;
If 80K found, check 85K;
85K found, check 87K,
not found, check 83K;.......
With 1-2 dozens operations
will get an approximate
No. very close to the acture .....