The Nets and Barclays Center, both part of Joe Tsai’s Brooklyn Sports & Entertainment, served hundreds of Brooklynites Saturday at a mobile food pantry set up on the arena’s entrance plaza. Working with Food Bank for New York City, the Nets and Barclays distributed both food and household supplies. In addition, families with children were given NBA Math Hoops board games, courtesy of the Nets. It’s a basketball board game that aims to engage students in math and social-emotional learning skills.