Countdown is a national treasure, and has thrilled us with thousands of episodes ever since its debut in the 1980s.
The programme is renowned as one of the toughest quizzes out there - particularly the maths round.
Over the years, Channel 4 viewers have tuned in as Countdown hosts Carol Vorderman and Rachel Riley give us head-scratching maths problems.
But some of the Countdown rounds have been solved - somewhat unbelievably - within moments.
In fact, some of the trickiest and toughest rounds posed to those competing have ended in a record time of under 30 seconds.
Below are some of the toughest we've seen over the years - and the players responsible for getting to a solution.
'Maths wizard'
James had 30 seconds to use the numbers 25, 50, 75, 100, 3, and 6 to calculate how to get as close to 952 as possible.
Here's how he did it:
100 + 6 = 106
106 x 3 = 318
318 x 75 = 23,850
23,850-50 =23,800
23,800/25
=
952
'Terrific' George
In October 2014, George was tasked with using 1, 2, 25 and 100, as well as 75 and 50, to get to 940.
George managed it by doing:
75 x 25 = 1875
He then added one for 1876, before multiplying by 50 for 93800, and divided by 100 to give 938, before adding 2.
"Well done!" exclaimed Rachel Riley.
"Terrific George," said Nick Hewer.
'Where did we find this guy?'
To get 813, Carol tasked two contestants with using 1, 10, 25, 50, 75 and 100.
John said he had 813, using:
75 - 10 = 65
65 x 25 = 1625
1625 + 1 = 1626
1626 x 50 = 81300
81300 divided by 100 = 813
"Where did we find this guy?" asked Richard Whiteley.
