U2 drummer Larry Mullen Jr. has finally figured out why he has been struggling with simple math skills for years.

RadarOnline.com can reveal the 63-year-old rocker was recently diagnosed with dyscalculia, a learning disability that makes it difficult to understand numbers and arithmetic.

Source: MEGAThe rocker explained he makes ‘odd’ faces behind the drum kit because he is attempting to count bars.

Mullen, who co-founded the Irish rock band in 1976, revealed he has struggled with basic numeracy skills like addition and counting for years – further explaining how the challenge has affected his successful music career.

He said: “I’ve always known that there’s something not particularly right with the way that I deal with numbers. I’m numerically challenged.

Source: MEGAMullen compared the difficulty of counting bars onstage to ‘climbing Mount Everest’.

“And I realized recently that I have dyscalculia, which is a sub-version of dyslexia. So I can’t count [and] I can’t add.”

The drummer even de-bunked the odd faces he makes during onstage performances, comparing his struggle of counting bars in a song to climbing the world’s highest peak.

He explained: “When people watch me play sometimes, they say, ‘You look pained.’ I am pained because I’m trying to count the bars. I had to find ways of doing this — and counting bars is like climbing Everest.”

Dyscalculia, a learning difficulty affecting 3-7% of adults and children, is more commonly diagnosed in those with dyslexia, ADHD, depression, or anxiety, according to a study cited by Healthline.

Mullen’s drumming style has been characterized by its precision and rhythm, and he has contributed to the band’s extensive catalog of albums and live performances.

Several notable musicians, including Cher, Robbie Williams, and Sophie Ellis-Bextor, have openly discussed their struggles with dyscalculia.

Cher faced challenges in school, while Williams revealed he struggles to read phone numbers unless they are spaced out. Ellis-Bextor, who has two sons with the condition, is also an ambassador for the UK’s Dyscalculia Network.

Mullen discussed his dyscalculia diagnosis while promoting his upcoming documentary Left Behind, which follows a group of determined mothers working to open the first public school for dyslexic students in New York City.

The rocker rose to international fame in the 1980s as a member of U2, the band he formed with his high school friends in Dublin: singer Bono, bassist Adam Clayton, and guitarist/keyboardist The Edge.

The band, which entered the Rock and Roll Hall of Fame in 2005, is known for hits such as With or Without You, I Still Haven’t Found What I’m Looking For, and Beautiful Day.

The Irish rock band was co-founded by Mullen in Dublin in 1976.

Despite his disability, Mullen’s drumming style has been characterized by its precision and rhythm, and he has contributed to the band’s extensive catalog of albums and live performances.

In addition to his music career, Mullen also made his film acting debut in the 2003 movie The Good Shepherd.