A dozen kindergartners held picket signs and marched down their third floor hallway, chanting about Martin Luther King Jr., “He was great, and he was good. He taught peace and brotherhood.”

Stopping in front of the nearest water fountain, one student taped to the wall a sign that, in child’s penmanship, read “White Only.”

“Did people get punished for drinking out of the wrong water fountain?” asked their teacher, Diamond Mays.

“Yes,” several of the children, all of whom are black, responded.

How, Mays asked, did black people who couldn’t use certain water fountains feel, especially on a hot day?

“Sad!”

“Frustrated!”

This scene on Thursday was one of several exercises the kindergartners at New American Academy Charter School in Canarsie participated in ahead of Martin Luther King Jr. Day. Each year, the school commemorates the day with lessons or activities tailored to each grade.

Since the students are so young, teachers have mostly focused on King’s promotion of peace and his legacy, rather than the more violent aspects of the American civil rights movement, said Fatima Toure, a kindergarten teacher at the school. It’s part of the school’s model to promote King’s vision and ideology, which is what “we want for our students,” said Lisa Parquette, the school’s headmaster.

The activities at New American are one slice of what schools across the city are doing to teach their students about King ahead of the national holiday, which marks when the civil rights leader would have turned 90. Brooklyn’s PS 261 participated in an annual march to Borough Hall. P.S. 770 in Brooklyn will hold a volunteering event Monday to commemorate the holiday, which children have off from school.

Toure said the activities also appeal to students’ natural curiosity. “They seem more curious as to, you know, why it was happening because I believe they just heard about Martin Luther King, but they didn’t really understand what he did,” Toure said. “They would ask questions about why African Americans have to sit in the back of the bus, why was everything separated, why were there colored signs in certain places.”

Since kindergartners do better with visuals, school leaders chose the march and water fountain activity so they could actually see slices of what life was like before and during the civil rights movement, Toure said.

Over the past week, kindergarten classes reviewed a few readings about King. With a teacher’s help, they wrote about the ideas King pioneered that left an impact on their daily lives.

A guest speaker visited students on Tuesday and answered questions about segregation and King’s biography.

They learned key terms like segregation and Jim Crow and helped make their “protest” signs featuring facts about the civil rights movement.

“Jim Crow laws legalized racial segregation,” one kindergartener read proudly from her sign before their march.

After the march, the students returned to their classroom to share their dreams (with inspiration from King’s “I Have A Dream” speech). Several of the children, a little confused by the lesson, wished that black and white people could use the same water fountains, and their teacher gently reminded them that this was already the case. One girl hoped to “get more big and grow up.”

Then it was Nathan’s turn.

“My dream is white and black people can come together,” he said.