Ned and Kristen
(page 25)

Here's a solution from fourth-grade students in Virginia Beach:

Dear Mr. Erickson,

We are Megan and Tanner,4th grade students in Virginia Beach.

The first thing we did was to read the question. The question asked,"How high is Ned now compared to the top of the table?" The second we did was to eliminate the clues that were not relevent.Then we read the rest of the clues.

They stated that Ned was a spider and Kristen was holding him at her sholder hight which is 135 cm.sheis standing on a stool that is 42 cm.high.Then Ned jumped off her hand and let out a strand of silk that was 108 cm. long,and the table is 73 cm. above the ground.

Then we drew a diagram. We figured that since she's holding the spider at 135 cm. plus the hight of the stool would be 177cm. high. Then they said Ned jumped and let out a string 108 cm. long , so he might have been hanging there.

So we subtracted 108 cm. from 177cm.=69cm.Then the table is 73 cm. so subtract 69 cm. from 73cm.=4 cm.below the top of the table.

Thanks to Megan and Tanner!

And than you, thank you, thank you for explaining what you did! I put one of the most important parts of your solution in red. Drawing a diagram is almost always a good thing to do.

Teachers and advanced students: notice, at the end, how Megan and and Tanner naturally use the concept of negative numbers without using the "official" word. The problem was inspired by the unit "Wet and Dry Numbers" in the Maths in Context curriculum.

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