I opened the door and struggled through with my bags. The girls were sitting across the room in a large chair with a computer on their laps.

“Daddy!” they yelled and threw the computer aside to run and greet me. Each chose a leg.

“Hey guys.” I patted them on the back. “Hey…Oof.” I fumbled with my bag and shoes and tried to get out of the entry way. “So, what were you guys doing?” I asked, trying to detach them from my legs.

Clara stood back and grinned. Her eyes darted back and forth, “Actually, it’s funny you ask. Because we were doing…” she leaned towards me dramatically, “…engineering!”

My eyes widened. “Oh wow. Engineering. That’s what I was just doing too!” I pointed out the door behind me.

“Yes! I know!” the two of them twirled in the air a few times, elevated by laughter.

Clara continued, “I know the secret now.”

“What secret?” I sat down.

She grinned again at her sister, and then back at me, “I heard you talking to mom in the kitchen the other day.”

Uh oh. My mind raced. “What could you possibly have heard?”

“Well, I heard you telling Mom about my Monster Math program. And you told her that Monster Math was really just the same thing as normal math.” She pointed, like she sometimes does, to put a dot in the air in front of her, “So, all of this time I have been studying monster math, but I have really been doing engineering.”

I smiled and nodded. “Wow. You really are brilliant,” I said, pulling her close. “But I’m afraid you have things a little mixed up.” I suddenly had a flash of memory from my day at work. Stacks of papers and a sea of spreadsheets. Black and white lines extending into infinity and never meeting where they should. I shivered quietly “The secret isn’t that all Monster Math is regular math.” I stared out the window as if expecting something to be there. Some creature that had followed me from my office grinning wildly through triangular teeth as it watched my children hungrily. “The secret is that there is no such thing as regular math.” There was a scratching sound at the back door and the roof creaked ominously. “Sweetheart, you should understand that all math is Monster Math.”