Graduating senior Vanessa Umana expected to leave last Friday’s commencement ceremony at Francis Polytechnic High School with a diploma, a few photos and some wonderful memories.

Imagine her surprise, then, when Principal Ari Bennett announced that Vanessa would also be getting an $18,000 Chevrolet Sonic, one of two grand prizes awarded in a year-long contest to encourage perfect attendance at Los Angeles Unified schools.

“I was so excited,” Vanessa said Monday. “I felt like I was dreaming.”

Over the last year, LAUSD has awarded monthly prizes to hundreds of kids who answered “here” every time their teacher took attendance. Rewards donated by local companies included bicycles, gift cards to Subway sandwich shops and guest passes to Knott’s Berry Farm and Aquarium of the Pacific in Long Beach.

Vanessa will receive her grand prize — she thinks her car is metallic blue — during a ceremony Thursday at LAUSD headquarters. The other car was won by Euri Tanaka from San Pedro High School. District officials said Euri is on vacation and will get his prize when he returns.

Five elementary students also will receive iPads as winners in the district’s Attendance Challenge: Azucena Anaya from Sunrise Elementary, Kymiya Mason from Yes Academy, Andrea Morales from Parmelee Elementary, Elizabeth Rios-Gomez from Canterbury Elementary and Jasmine Vallejo from Park Avenue Elementary.

Six campuses also will receive cash prizes of $3,000 each which they can spend next year on programs to encourage attendance: Balboa Gifted Magnet, Ford Boulevard, Hesby Oaks, Quincy Jones, Miramonte and Vena Elementary schools.

District officials said 357 seniors with perfect attendance were eligible for the drawing to win the cars, which like many of the other prizes were donated by Clear Channel Media.

Among the hopefuls was Angie Armento, who never missed a day of class from the day she enrolled in preschool until she graduated last Thursday from Kennedy High School.

“School always came first,” said Angie, who has been accepted at Cal Poly Pomona and plans to become a veterinarian. “I never wanted to miss school because I never wanted to be behind. The future matters and it should matter to everyone.”

Debra Duardo, executive director of Student Health and Human Services, said the district made significant gains in reducing chronic absenteeism among its most susceptible students, and she credited the Attendance Challenge for much of the improvement.

“When students miss school, they miss critical instruction time that cannot be made up,” she said. “That impacts teachers who have to spend extra time with the student, and their classmates who said, ‘Why do we have to go over this lesson again?’ ”

She emphasized the correlation between good attendance and academic success, but also noted that the district receives an average of $32 for every day a student is in school. That means the district loses out on that money whenever a student is absent.

LAUSD lost about $156 million through student absences this year, including $14 million from kindergartners alone, she said.

Vanessa said it wasn’t until she got to high school that she realized just how important it was to attend every class, every day. Because her grades would determine whether she got into college — or not — she knew she had to participate in order to get ahead.

“Missing a day of school was like missing a whole lesson,” said Vanessa, who also worked on the Poly yearbook staff and volunteered as a tutor at Fernangeles Elementary and for LA’s Best after-school program.

Vanessa credits her work ethic to her mother, Minerva, a pharmacy technician, and father, David, a Navy mechanic who served three overseas deployments while she was growing up.

“That shaped me as a person and taught me how to have goals and be independent,” she said. “They always encouraged me to go to school so it would lead me to have a better life.”

Graduating with a GPA of 4.2, Vanessa has been accepted at UC San Diego. She plans to major in biology, with a long-term goal of becoming a doctor.

“My education is why I didn’t miss school,” she said. “Winning the car was just a big plus.”

barbara.jones@dailynews.com | @LADNschools on Twitter