Prince William revealed he struggles with home schooling children George, six,Charlotte, five, and Louis, two, during the lockdown.
And the Duke gets particularly baffled by their maths questions, he said on his documentary Football, Prince William and Mental Health.
Speaking on a video call with a host of football stars to discuss mental health, William asked how everyone was.
"Home schooling is fun isn't it," he said.
"You start worrying how little you actually know from your school days when you literally can't do the maths questions at home!"
He laughed: "The challenges of lockdown eh, the challenges of lockdown."
He spoke in the documentary of his fears for NHS frontline workers during the pandemic.
He warned that labelling the key workers "heroes" could add extra pressure on them, making them feel like they had to be strong all the time.
He explained that if they were struggling mentally, which so many would be, they may find it harder to talk about if they have the pressure of a "hero" label.
He also talked about the "trauma" of losing his mum when he was 12, and revealed the emotions came flooding back when he became a parent.
He was speaking to former Bolton and Burnley player Marvin Sordell, who had depression after growing up without his father.
"I grew up without my father and I've not had a father to look up to, and now I've got a child looking up at their father.
"I really struggled with my emotions at that time," he added, before asking William for advice on dealing with this.
"Having children is the biggest life-changing moment, it really is.
“When you’ve been through something traumatic, like your dad not being around, my mother dying when I was younger, your emotions come back in leaps and bounds.
"Because it's a very different phase of life and there's no one around to help you.
"I definitely found it overwhelming at times."
