When the kids call

The phone rang Monday night. I looked at the Caller ID. It was my son.

I answered, "Hello."

Slight pause on the other end. "Hey."

"Hey, there. How is everything?"

He paused. "Pretty good." Another pause.

"Something's on his mind," I thought. So, I ask, "What's up?"

"Um," he said, then paused again. "I got a question."

"Sure," I responded, not sure at all.

"Um. Say I have two clocks. One keeps perfect time. The other loses 4 minutes an hour."

"Uh, okay."

He continued, "At 12 o'clock, they have the same time..."

"Okay," I said as I tried to follow along.

"Now, when the clock that is off 4 minutes each hour gets to 2:20, what time does the other clock say? I think it's 2:30, but I'm not sure."

My turn to pause. "Uh. Well, you say the wrong clock is 4 minutes off. Each hour? After one hour, it's at 56?"

"That's right. And I think 2:30 is right, but I'm not quite sure how to explain why."

"Well, if it's off 4 minutes each hour," I said, thinking out loud more than anything else, "it's off 1 minute each 15 minutes, right?"

"That makes sense."

"And we're looking at what time? 12:20, uh, 2:20?"

"Right."

"That's ... uh ... 140 minutes, right?"

"Yeah, 120 and 20 ... 140."

"So, that's 10 times 14. So the other clock, the one that's right, would have moved 10 times 15, right?"

"That's right."

"And 10 times 15 is 150, or 2½ hours. That's 2:30."

"Okay, I got the right answer. Good," he said.

"Yep," I confirmed.

"Well, I appreciate it," he said.

"Sure thing."

"Alright, then. We'll talk at ya later."

"Okay, son," I said, "We'll see you."

And the call ended.

It's always great when the kids call.