Liberal Democrat leader Nick Clegg was grilled by a group of schoolchildren as preparation for tonight's landmark TV debate.
Mr Clegg admitted he was "rubbish at maths" as he took questions from pupils at a Manchester primary school.
He said he was "a little bit" nervous ahead of his televised showdown with Gordon Brown and David Cameron.
Mr Clegg has scaled back his campaigning to give himself time to prepare for the debate.
The question and answer session at Mauldeth Road Primary School in Withington was his only public event before the show.
The Lib Dems have insisted that their manifesto, launched yesterday, was fully costed and contained credible tax and spending plans despite claims from Tories and Labour that the sums do not add up.
But asked what subjects Mr Clegg enjoyed at school, the Lib Dem leader said: "I was rubbish at maths."
He added: "I scraped through but I was not great at maths."
The children, mostly aged between nine and 11, questioned Mr Clegg on a range of topics including the environment and anti-social behaviour.
Mr Clegg's plans for smaller class sizes and one-to-one tuition concerned one girl, who asked if the policy would "separate friends" from each other.
The multi-lingual Lib Dem leader showed off his Spanish after being questioned in the language by 10-year-old Ali Bakri, who asked if he liked football.
The main focus of the session was on the leaders' debate, which is being broadcast live from Manchester.
Asked if he was nervous, he said: "I am a little bit, yes. That's why I have come here for a bit of a practice.
"I'm also quite excited, it's never happened before so it's quite a big opportunity."
The pupils all put their hands up when asked if they were going to watch the debate.
Mr Clegg said: "It's on until 10 o'clock, isn't that a little bit past your bedtime?"
He added: "I don't think these are things that you can prepare for that much.
"What I really want to try and do is enjoy it."
Mr Clegg will hope a poster displayed in the school hall will prove to be a good omen.
The poster had creatures representing different emotions, with an angry red character, a sad blue one and a happy yellow creation.
The Lib Dem leader will go for a long walk in the country before heading back to Granada Studios for the debate.Reuse content