Randi Boxer, an art teacher at PS 152 in Brooklyn, spends all week teaching kids to paint. So, when she heard about the union’s Thanksgiving Luncheon organized by the UFT Middle Schools Division on Nov. 23, she decided to spend that day as well doing what she does best, “letting students be creative.”

“I’ll come out for anything to benefit kids,” said Boxer, who helped children at the luncheon paint cardboard cone turkeys. These children “need a little extra fun, especially at the holidays.”

That’s because the 200 students who attended the luncheon live in shelters or doubled up with friends or family.

As it has done for the past six years, the UFT entertained children between the ages of 3 and 18 from all over the city at UFT headquarters in Manhattan, in partnership this year with the city Department of Education. The number of school-age children in New York City who are homeless has grown by 70 percent over the past decade.

“We wanted to give them a Thanksgiving meal, but we wanted to add more fun,” said Richard Mantell, the UFT vice president for middle schools.

The guests got their faces painted, built animals out of Legos, made craft projects, got their nails and hair done and put on temporary tattoos before enjoying a holiday meal. The day’s finishing touch was when each child got a new winter coat in the proper size.

UFT members donated a record number of coats and contributed nearly $37,000 this year. The UFT chapter at PS 209 alone, led by Chapter Leader Elisa Balsamo, raised $2,700 to help pay for winter coats and accessories.

Giving out the coats is the “best part of the day,” said Mantell, who organizes the luncheon and the coat drive. But it can be “bittersweet” to see the disbelief in the children’s reactions, he said. “A couple years ago, I handed a kid a coat and he asked, ‘You mean I get to keep it?’ ”

One 7th-grade girl enjoyed herself much more than she expected. “At first I thought it’d be boring,” she said. “Then I saw all the stuff and got my nails done! I’m having a lot of fun and it’s exciting.”

Teresa Bello, a pre-K special education teacher at PS 185 in Manhattan who came to help out with a craft project, said “not having a place to live” is an issue close to her heart. “It’s important for students to have these positive adult interactions and see possibilities for after they get out of the world of transitional housing,” Bello said.

Her takeaway from the day? “Pay it forward!”