02:59 - Source: CNN
Retail boss: Leading is a privilege

Story highlights

Meet Rosalind Brewer, the CEO of Sam's Club, part of Walmart

Chemistry graduate now heads company worth billions of dollars

Says 'honesty and integrity' are integral to her career

Laying off 2,300 workers was one of toughest moments of her life

Editor’s Note: In celebration of International Day of the Girl (October 11) and Ada Lovelace Day (October 14), Leading Women is devoting the month of October to women and girls in STEM: science, technology, engineering and math.

CNN  — 

There’s a fine science to running a billion dollar company. Rosalind Brewer should know – she used to study chemistry.

Before she was CEO of American retail giant, Sam’s Club – a company which boasted $56 billion in revenues last year – Brewer earned a degree in science at Spelman College, Atlanta, Georgia.

These days though, one of the first things she thinks about when she wakes up is her 107,000 employees.

“I owe them leadership, direction, and the chance to grow,” says the chief of the retail warehouse chain, owned by Walmart.

“I take that as a personal responsibility. And I have to earn it every day.”

When 51-year-old Brewer took the job in 2012, she became the first woman and the first African American to lead a Walmart division.

Two years later, the number of Sam’s Club stores has grown from 610 to 643 across the U.S. and Puerto Rico.

Could the 64th most powerful woman in the world, according to Forbes, one day have the top job at Walmart?

“Oh boy, that is a good question,” she says, laughing a little nervously.

“If ever I was afforded the opportunity, surely I would step up to the challenge.”

Here are four more insights from the former chemistry student.

“One of the best pieces of advice I’ve received throughout my career was the importance of having honesty and integrity. It helped build me as a person and helped me stay consistent to my values.”“

“The first response from people is that I have a visible difference – I’m an African American female. I think they have this initial response which is ‘What is she made of? How did she get here?’”

“Laying off 2,300 workers was very difficult. I take those moments really personally and we did a lot of work to make sure we were doing the right thing.”

“What scares me? Tornados. I think I can do a lot of things. But if that tornado is coming for me, I don’t think I can stop it.”

Rosalind isn’t the only female science graduate aiming big.

For the month of October, Leading Women celebrates women and girls in STEM: science, technology, engineering and mathematics.

Join @CNNIwomen’s Twitter chat with STEM experts on October 9 at 5pm GMT/12pm EST. #CNNWomen #IDG14