I can't read graphs

When she was passing out last week's tests for review tonight (which she later collected again, a professorial habit I dislike), Ms. H asked me what grade I was planning to teach. I said I was aiming for 3rd or 4th. She replied that I'd be good teaching 5th graders; "you have the kind of humor they appreciate."

I really doubt I'd like teaching fifth grade; they're too hormonal and lack empathy. But Ms. H was referring to some of the word problems I wrote on the test.

To illustrate a "take-away" subtraction problem, I wrote, "Jack has five crackers. Suddenly, a demented crow swoops down and grabs three of them in its talons and flies off, cawing triumphantly. How many crackers does Jack have left, and how long will it be before he gets over his subsequent ornithophobia?"

To illustrate a "missing addend" subtraction problem, I wrote, "We have ten basic freedoms. The Powers That Be foster a national state of panic and pass laws that effectively take away a few of our natural rights, allowing us six (for now). How many freedoms did these laws strip away?"

You have to amuse yourself somehow during exams.

I got a 97 on the test. The problem I was concerned with, which required listing all the possible combinations of less than ten coins that equal 42 cents, I seemed to muddle my way through. It turned out there wasn't a formula one could use to figure it out. What I did, the guess-and-check graph, was apparently the way to do it, and I got all the possibilities.

I lost three points making a glaringly obvious careless error. The question asked the value of a line on a given graph. The question even noted that this line began with a value of 20 and not zero. I nevertheless failed to take this into account and just wrote down the value at the intersection point (when I should have subtracted 20, of course).

After going over the test, we reviewed division strategies, a few basic rules of exponents (such as 2³ x 2⁴ = 2³⁺⁴ = 2⁷), the greatest common factor and the least common multiple. Basic stuff.