Last week, he was sleeping on the floor at a San Francisco drop-in homeless shelter with his parents and 3-year-old brother Danny. Thin mats kept them off hard linoleum.
In the last two months, he spent three nights at a bus shelter and a week on the streets, sleeping on his parents' laps in a park.
Yet every morning, Rudy Nguyen takes two Muni buses to San Francisco's Spring Valley elementary school, where the fourth-grader is expected to be ready to read, write and multiply numbers - like every other kid in school.
Rudy is among a growing number of San Francisco schoolchildren in homeless families who too often come to class cold, hungry and sleep-deprived, making learning difficult if not impossible.
"If you're not fed, if you're not warm, if you're not sleeping ... you can't turn that off and focus on double-digit multiplication," said Jessica Chiarchiaro, Rudy's fourth-grade teacher.
In the city's public schools, there are 2,200 homeless children, some in shelters, others in cars, or on couches, or in long-term hotel rooms. That's 400 more homeless children than a year ago.
They are among the most difficult children to teach, educators say, because their unstable lives often lead to frequent absences or tardiness, lethargy, health issues and behavioral outbursts.
Doing homework can be tough without a kitchen table.
And yet in the spring, these homeless children will take the same standardized test as students in Hillsborough, Piedmont and Beverly Hills where every physical and academic need is met - their heated bedrooms full of books, computers and educational toys, their kitchens stocked with food.
"We're being held accountable for these kids scoring a certain percentage correct on a standardized test," Chiarchiaro said of the homeless schoolchildren. "I wish public schools had more resources so we can help them."
Homeless students typically post scores below or far below grade level on those tests, landing at the opposite end of the achievement gap from kids with greater advantages.
Late for school
One recent morning, Rudy's parents, Sophorn "Julie" Sung and Tung Nguyen, juggled a bag of clothes, jackets and Rudy's 3-year-old brother, Danny, as they left the Oshun drop-in shelter in the Mission District. They weren't allowed to leave anything at the shelter for the day, so they headed to a local storage facility.
Rudy and his family waited outside until 8 a.m. when the storage gates opened. At Rudy's school, breakfast was being served.
Rudy hadn't eaten yet.
The family came to San Francisco from Dallas in September after Rudy's unemployed father believed he had a good-paying job in shipping and receiving waiting for him. The job didn't pan out.
They had sold everything to come to California, except for the few belongings in the storage locker.
"Oh, he's going to be late again," Sung said as she stashed the clothes for the day.
School was just starting when Rudy arrived 45 minutes later. He had been delayed because the 49 Mission Muni bus he and his family hoped to catch pulled away as they crossed the street. They caught the next bus.
On the way to school, Rudy didn't talk much.
"Mom, I'm hungry and cold," he said as he walked up the final hill toward Spring Valley elementary school.
His mom didn't respond.