If I could have been anything, I might have become a physicist or mathematician. The logic, the rules, the exploration of things you can’t see but can prove are real has always been incredibly attractive. I have books on math and physics that I read for pleasure, two of my heroes are Feynman and Erdos, and I’m certain that Isaac Newton was a genius without parallel. So I feel really bad when I convince a kid that he has eleven fingers. I’ll explain.
Working with kids as patients, I try to make them comfortable with jokes and tricks. I have different tricks that I can do like float my thumb, pull my eyebrows and lips around with invisible string, etc. One of my favorite tricks, though, is the eleven-fingers trick. Here’s how you do it.
“How many fingers do you have?”
“Are you sure?”
“?” They then count their fingers to make sure. “Yes! Ten!”
“I bet you have eleven.”
“Watch, I’ll show you.”
You then count their fingers in a special way. Instead of one-two-three, you add an “eight” after each number. Read this sequence ALOUD and see if you catch it.
“One eight two eight three eight four eight five eight six eight seven eight nine eight ten eight eleven eight. See? You have eleven fingers!”
Sometimes they’ll count their fingers again to make sure, sometimes they’ll just start laughing at the trick. I feel pretty bad about what happened today. A little boy from first grade had a cut above his eyebrow that opened up a fair bit. It wasn’t bothering him much anymore and he was easy to examine. We were killing time, waiting for the physician to come in and suture his brow when I started the eleven-fingers trick. He was enthusiastic about his ten fingers and appropriately baffled by his eleventh. However, when I saw that he was more bothered than entertained, I tried to explain it to him.
“Tim, I tricked you because I never said ‘eight eight.’ I skipped it. Here, I’ll show you.” I then went through the sequence again, inserting the “eight eight.”
“Ok, Tim. How many fingers do you really have?” He looked at me, then at the other students in the room, and finally at his teacher who brought him in from school. His face screwed up and with some pain he answered, “Eleven?”
He had to go back before I could fix the damage. I hope he doesn’t swear off math forever.