they’re the same; they just have different numbers

Posted on February 25, 2015


… not yet.

Here’s a “this person might have issues with math” situation:  We’re supposed to figure out how long it will take Forrest Gump to mow a football field with a 30-inch wide mower; field 120 yards by 160 feet, going 4 mph.

Converted 120 yards to 40 feet… fixed that…

Draw the field?    gumprectangleI asked what the numbers meant and got silence.   I shaded along the line with the 160 and asked, “how long would this be?”   “160.”  (I don’t remember wehther or not she included units at first but I’m pretty sure they didn’t last.)

“And this side?”   “360.”

“And this side?”  (the side labeled 2.5)  “2.5.”

“But isn’t this a rectangle?   What does that mean?”   (Silence…)

I showed the student that the piece of paper was 11 inches on both sides, 8 1/2 inches on both other sides.

I asked about the picture.

“Yes, they’re the same.”   However, one was 160 and the other was 2.5.

“But how can that be the same?”

“They’re the same, they just get different numbers.”

……………………………..   I’m afraid I was floored… I asked her to look at me and listen carefully, and I said, “That’s. Not. How. Math. Works.”   I’m afraid my shift in tone obliterated any chance of a light bulb going on, and I knew it, so I stopped the interrogation route and showed her that the 2.5 was describing the lawn mower, not the football field, and explained that if it was 160 feet on one side, it would be 160 feet on the other, and we worked through the problem. She *did* know when to multiply and when to divide for figuring out how many trips Forrest Gump would have to take with the mower, and how many feet he would have to travel, and then how long that would take.

There are *so* many possibilities … Was she answering the last questions because the patterns were familiar (or with 50/50 odds she picked the right operation)?    Was she thinking of different units with the different numbers?   After all, 120 yards and 360 feet *are* the same distances.

Workin’ on that patience thing…

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