There she saw a mysterious language of polynomials and slope intercepts that looked about as familiar as hieroglyphics.
"I felt like, 'Oh, my God, what am I going to do?' " she recalled.
Gabriela failed that first semester of freshman algebra. She failed again and again — six times in six semesters. And because students in Los Angeles Unified schools must pass algebra to graduate, her hopes for a diploma grew dimmer with each F.
Midway through 12th grade, Gabriela gathered her textbooks, dropped them at the campus book room and, without telling a soul, vanished from Birmingham High School.
Her story might be just a footnote to the Class of 2005 except that hundreds of her classmates, along with thousands of others across the district, also failed algebra.
Of all the obstacles to graduation, algebra was the most daunting.
The course that traditionally distinguished the college-bound from others has denied vast numbers of students a high school diploma.
"It triggers dropouts more than any single subject," said Los Angeles schools Supt. Roy Romer. "I think it is a cumulative failure of our ability to teach math adequately in the public school system."
When the Los Angeles Board of Education approved tougher graduation requirements that went into effect in 2003, the intention was to give kids a better education and groom more graduates for college and high-level jobs. For the first time, students had to pass a year of algebra and a year of geometry or an equivalent class to earn diplomas.
The policy was born of a worthy goal but has proved disastrous for students unprepared to meet the new demands.
In the fall of 2004, 48,000 ninth-graders took beginning algebra; 44% flunked, nearly twice the failure rate as in English. Seventeen percent finished with Ds.
In all, the district that semester handed out Ds and Fs to 29,000 beginning algebra students — enough to fill eight high schools the size of Birmingham.
Among those who repeated the class in the spring, nearly three-quarters flunked again.
The school district could have seen this coming if officials had looked at the huge numbers of high school students failing basic math.
Lawmakers in Sacramento didn't ask questions either. After Los Angeles Unified changed its policy, legislators turned algebra into a statewide graduation requirement, effective in 2004.
Now the Los Angeles school board has raised the bar again. By the time today's second-graders graduate from high school in 2016, most will have to meet the University of California's entry requirements, which will mean passing a third year of advanced math, such as algebra II, and four years of English.
Former board President Jose Huizar introduced this latest round of requirements, which the board approved in a 6-1 vote last June.