The TV star and maths whizz was on the hit programme with the late Richard Whiteley from 1982 until 2005, and then with Des O’Connor and Des Lynam until 2008, when she left.
Opening up about the role on the Off Menu podcast, she said she had “such a laugh” on the programme and that in the early days there was a bar that everyone on the team – and others in the industry – frequented in the evenings.
Vorderman said it was a special time, and shared: “Rude word Countdown happened in the bar afterward."
The 62-year-old also told how she would have to keep her cool on the show on the occasions when the letters spelled out a cheeky word.
“Some did come up, and then we would have to keep a straight face,” she laughed.
“It was all about keeping a straight face.”
“And then of course you know, in the early days they would go, ‘No, cut, cut, cut’ and we would have to do it again,” she explained.
Vorderman made her small screen debut on Countdown in November 1982.
Last year she paid tribute to the programme as she marked her 40 years on TV.
Sharing a clip from Countdown on Instagram, the TV star told her fans that it was the first show on then new channel, Channel 4.
"Happy birthday Channel 4 and Countdown… And happy TV birthday to (me)," she wrote.
Watch: Carol Vorderman says romances with her five 'special friends' came about 'naturally'