Ch 11 Sly says that five times negative five is zero and I think, “I was an English major and I know that’s wrong”

Michael: Grandpa, I’m right.

Sly: Primo, five times negative five is zero, right?

Primo: What, Dad?

Sly: Five times negative five is zero.

Oh. This. Is. So. Good.

I have been trying to keep my mouth shut this visit. But this? How can I resist this?

Me, not even looking at Sly: Five times negative five is negative 25, Sly.

Michael: I told you, Grandpa.

Sly: No. The negatives cancel each other out. It’s zero.

Me: It's negative 25. You're wrong, Sly.

Oh the JOY of saying those words! WRONG WRONG WRONG! And on something so simple, so basic, so objective, so provable!

I smile in triumph. I catch Doris’ glance: she is smiling, too. She is a scientist. She knows math. When our eyes meet, her eyes fly open and her hand goes to her mouth. She hides that smile as fast as she can. What if Sly sees her laughing at him?

Sly ignores me and continues looking at Primo, because I cannot possibly have the right answer. Primo confirms what I said, which is not hard to do because five times negative five is indeed negative 25.

Sly insists: No! It’s zero! The negatives cancel each other out!