by David Lubar
Behind me, I heard a rattling sound. I looked over my shoulder. Ms. Fractalli was yanking at her new lock.
“What’s wrong?” I asked.
“I was afraid I’d lose the piece of paper with the instructions, the way I was always losing the key, so I put it in my purse,” she said. “Then I locked my purse in the cabinet, as I always do.”
“You didn’t memorize the combination?” I asked.
She shrugged. “I didn’t get a chance to memorize it or even look at it. I was up pretty late grading the tests.”
“Let me see.” I liked playing with locks.
“It’s hopeless,” she said. “There are too many combinations.”
I lifted up the lock and looked at it. There were five buttons on front, labeled A, B, C, D, E. “How does it work?” I asked.
“I’m supposed to push some of them in,” she said. “But I don’t know which ones or how many.”
“I can get a saw,” Benedict said. “Yeah—a power saw. Or those giant pliers they use on cars. Wait! Better idea! We could go to the high school and get some hydrochloric acid from the chemistry lab. That will eat right through it.”
He kept talking, but I stopped listening. The lock had all of my attention. I knew there were letters on it. But it reminded me of the kind of number problems we’d solved at the museum.
“It’s binary!” I shouted as the answer hit me.
“Cool,” Benedict said. He stopped talking and looked over my shoulder. “Yeah, you’re right.”
I turned toward Ms. Fractalli. “If there was just one button, you’d only have two choices. Right?” I pushed down the button with A on it and then popped it back up.
“And two buttons would only give you four choices,” Benedict said.
“For sure,” I said. It was definitely like the binary numbers we’d learned about. “And three buttons would be … ”
“Eight!” Benedict said. “Like Dr. Thagoras’s light switches.”
I held up my right hand and stuck out one finger at a time, doubling the number with each new finger.
Pinkie.
“Two.”
Ring finger.
“Four”
Middle finger.
“Eight.”
Benedict and Ms. Fractalli joined in.
Index finger.
“Sixteen!”
Thumb—my whole hand was spread wide.
“Thirty-two!”
“That’s not a lot at all,” Ms. Fractalli said. “I should have realized it right away.”
“Sometimes, we all forget our math skills,” I said. I thought about those pennies that doubled every week for a year. It’s a good thing the lock didn’t have fifty-two buttons. Or even ten.
I started pushing the five buttons, going through the thirty-two possible combinations:
up-up-up-up-up
up-up-up-up-down
up-up-up-down-up
up-up-up-down-down
up-up-down-up-up
up-up-down-up-down
up-up-down-down-up
up-up-down-down-down
I tugged on the lock after each combination. I hoped I wasn’t missing something. It seemed too easy. But then, after more than twenty attempts, I tried
down-up-down-up-down.
The lock pulled open.
“I did it!” I shouted.
“Logan, that was wonderful,” Ms. Fractalli said.
I noticed that the A, C, and E were pushed down. “Ace,” I said. “I’ll bet you’ll never forget that combination.”
“And I’ll never forget how you two helped me,” she said.
“That’s the power of two,” I said.
She looked at the clock. “How’d you boys like another chance at the last part of the test?”
If anyone had ever told me I’d be cheering at a chance to take a math test, I never would have believed it. But I was sure cheering then.
“Ready?” I asked Benedict as we walked back to our desks with new copies of the test.
“Let’s ace this,” he said.
“Shhh,” I said. “That combination is a secret.”
But when Ms. Fractalli graded our tests, that’s exactly what we did. Benedict and I aced it, saving our grades and the ice cream party.
And wouldn’t you know it, when the time came for the party, we both ended up getting brain freeze again. But at least, this time, we didn’t get numbed.
David Lubar has written a fairly large, though finite, number of books, including Punished! and Hidden Talents. He’s always enjoyed math, but he never dared write a book about it until now. The chance to send Logan and Benedict on another adventure was just too tempting for him to resist. He lives in Nazareth, Pennsylvania, with his wife and various felines.
Jacket art by Jeffrey Ebbeler
MILLBROOK PRESS
A division of Lerner Publishing Group
241 First Avenue North • Minneapolis, MN 55401
www.lernerbooks.com
Printed and bound in the U.S.A
