When I was nine, I could not understand how medicine could make someone look sicker.

My grandmother had Stage 3 pancreatic cancer. She was the person who picked me up from school, cooked for me and taught me games, especially Mahjong. Then suddenly I was sitting in hospital waiting rooms hearing words like chemotherapy, tumors and side effects while watching her become more tired and weak.

Adults told me the treatment was supposed to help her. To a nine-year-old, that did not make sense. If medicine was helping, why did she feel worse?

What I remember most is that some of her doctors did not brush off my questions. They sat down and explained, in words I could understand, that chemotherapy can damage healthy cells while trying to kill cancer cells. The explanation did not make cancer less serious. It made it less mysterious.

My grandmother died about six months after her diagnosis. For a long time, games were one of the ways I still felt close to her.

Years later, cancer entered my family again when my grandfather was diagnosed. This time, I was 15, and my seven-year-old sister was the one sitting in the doctor’s office looking confused. I recognized that look immediately.

So I became the person who pulled up a chair.

I read my grandfather’s medical reports and tried to translate what I understood into language my sister could follow. I did not have perfect answers. But I realized that understanding even a little could make a frightening situation feel less impossible.

Some children encounter cancer long before they take a biology class. A parent, grandparent, sibling, teacher or friend can be diagnosed, and suddenly kids hear unfamiliar words while also watching someone they love change physically and emotionally. Trying to protect children by saying very little can leave them to fill in the blanks themselves.

The American Cancer Society recommends honest, age-appropriate conversations with children about cancer, including what treatment may do and how it may change the way a loved one looks or feels. It also suggests using play and art to help children process what is happening.

That idea eventually led a few classmates and me to create Tumor Tactics, a card game that lets students learn how treatments such as chemotherapy, immunotherapy and targeted therapy work. We did not make it to turn cancer into something lighthearted. We made it because games were a language I already understood as a kid.

In workshops with younger San Diego students, I have seen how quickly fear or hesitation can turn into questions when kids are given permission to engage. Why does chemotherapy cause side effects? Why do some treatments work for one cancer but not another? Those questions matter.

Hospitals, schools and families do not need a card game specifically. But children do need adults willing to explain hard things honestly, patiently and in ways they can understand.

I cannot go back and explain cancer treatment to my nine-year-old self. What I can do, and what more adults can do, is make sure the next child is not left alone with words they do not understand.

Daniel Zhang, 17, is a senior at Canyon Crest Academy in San Diego and co-founder of STEAMLabs International, where he helped create Tumor Tactics, a cancer-education card game for younger students.