Demi Lovato and Britney Spears have officially signed on to join the "X Factor" as judges this season.
Britney Spears has been studying Maths.

After conquering the charts, pop superstar Britney Spears is now preparing to take on algebra.

The 33-year-old Grammy winner, who is worth an estimated $130m (£87m), has revealed she has signed up for maths lessons so that she can help her sons with their homework.

Spears, who dropped out of school in the ninth grade to pursue a music career, told People Magazine she wants her children to receive good grades.

"They go to a really hard school, and this week we had three hours of homework [a night]" she told the magazine.

The Hit Me baby One More Time songstress added: "Some of it is hard for me. Next year when [Preston] is in fifth grade, he's going to be doing pre-algebra, and I'm taking classes so I know how to do it!"

And it looks like she also ready has an effective reward system in place to guarantee that her sons keep getting top grades.

"If they get so many A's, they get one toy a month," she revealed. "Preston just asked for a high allowance like $10 a week or $20 a week - but we'll see."

Spears gave up on attaining high school diploma in 2004, shortly before marrying Kevin Federline, the father of her two sons.

Meanwhile, Spears has reignited speculation that she is secretly engaged to producer Charlie Ebersol after she was spotted wearing a diamond ring on her finger while on holiday in Hawaii.

She was dated Justin Timberlake from 1999 to 2002 was previously hitched to Jason Alexander. Despite her track record, the mother-of-two recently claimed that she is still open to the idea of marriage.

"I would love to. I believe in the fairy tale. Love is a hard one. I don't really understand love as far as relationships," she said.

"With my kids it's just unconditional, and that's hard to find. It takes two people just loving each other a lot. Unfortunately I haven't been given that in a really long time."