Isaiah Martin was devastated. Tears streamed from the sixth-grader’s eyes.

“I asked him what was wrong, and he said, ‘Grandmama, I got a B,’ ” Mildred Martin said.

“And it was an 89,” added his father, Vaughn Martin, with a light chuckle. “But he wanted an A.”

A student at Luella Middle in Henry County, Isaiah loved school. To his father and grandmother, young Isaiah’s grades were remarkable, especially considering he’d been battling brain cancer for months.

It was toward the end of Isaiah’s fifth-grade year that he started complaining of headaches and vision problems. One day in March, Vaughn Martin got a call from the school to pick up his son because the boy’s balance was off and something was wrong. After a trip to the hospital, Martin, his girlfriend Melanie King, and Isaiah received shocking news: Isaiah had an inoperable type of tumor known as diffuse intrinsic pontine glioma (DIPG).

“The doctor explained everything and asked if we had any questions,” Martin said. “And Isaiah asked, ‘Can I die from that tumor?’ and the doctor said, ‘Yes, it is possible that you can,’ and I began to cry, but Isaiah said, ‘Daddy, don’t cry, the doctor doesn’t know what he’s talking about.’ ”

Soon the Martin family was told Isaiah had a couple of weeks to live, but Isaiah had a different plan. He lived another 18 months, during which time he vacationed in his home state of California, played in a basketball tournament and completed sixth grade. Flanked by his dad and King, Isaiah also endured countless doctors’ appointments and radiation treatment for a month.

As his health declined, many of his teachers came to visit him weekly and over the summer. He often asked about the upcoming school year.

“A couple of weeks ago he made one of the teachers promise to bring his schedule so he could see his classes,” said Summer Robinson, a counselor at Luella. “He wanted to keep moving forward.”

Isaiah Ali Martin of McDonough died Wednesday from complications of the cancerous tumor. He was 12.

A funeral is planned for 11 a.m. Saturday at Shiloh Baptist Church, McDonough. Burial will follow at Salem Cemetery, McDonough. W.D. Lemon & Sons Funeral Home, McDonough, is in charge of arrangements.

Isaiah was known at home and at school as a helpful child. Protecting friends and reuniting lost dogs with their owners were among the things he liked to do.

“He’d come in all, ‘Grandmama! Grandmama! Where’s the leash, I know whose dog that is!’ And he’d run off with the dog and come back without my leash,” Mildred Martin said, enjoying the memory. “So now I can’t walk my dog. But you know, he was a delightful child.”

Robinson said when she met Isaiah at the beginning of last school year, his goal was to have a school experience that was as close to normal as possible.

“Working with him and watching him, I think I’ve become a better counselor and person,” she said. “Seeing how he approached every day, and lived every day, and continued to push, that will be part of my counseling philosophy from now on; no matter what we’re faced with, we can do our best and keep pushing.”

In addition to his father and grandmother, Isaiah is survived by his mother, Tra’dasha Martin of Virginia; sisters, Cabrina Martin of Savannah, Asia Martin of Anaheim, Calif., and Elise Martin of Atlanta; brother, Joseph Terrell of Atlanta; and grandfather Carlton Martin of Brooklyn, N.Y.