ZeroSum Ruler (home)

Blogging on math education and other related things

The recession-proof Exam: When will it pop?December 19, 2010

The article by Todd Farley “Standardized Testing: The New Wild West” pretty much sums up why high-stakes testing has such a stronghold.  It’s a recession proof industry!  I knew that millions went into it, but I didn’t know the full extent of greed that’s going into it.  Farley himself admits to capitalizing.

But like all bubbles, this one will pop.  Hopefully.  Then maybe our kids can go back to learning again.

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In somewhat related news, here’s a great chart of just how many math topics we throw at our kids each year as opposed to A+ countries where students excel in math…

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Subtraction as “as compared to”December 10, 2010

I learned the best thing today at an interview, which I know sounds a bit weird.  Usually at interviews it’s all about what I’ve done and where I see myself in 5 years and whatnot.  This interview was far different, and better, and awesome.  Today at my interview, I learned something really great about… subtraction.

Let’s take a problem like “7 - 2“.  We can read the subtraction sign as “as compared to“.  When we find 7 and we find 2 on a number line, comparably they are 5 apart.  And indeed, 7 - 2 = 5.

But does it work for subtracting negatives?  let’s check…

“7 - -2″.  Seven as compared to negative 2.    7 and -2 are 9 apart, and in fact    7 -  -2   =   7 + 2 =   9!

This is a SUPER model that, as my boyfriend just said, opens a whole new world.  Who knew at 33 I’d still be learning subtraction!

Awesome!

US vs A+ Countries: Breadth vs Depth in Math. Which is better?December 6, 2010

(Click chart to enlarge)

Schmidt, William H., Wang, Hsing Chi., McKnight, Curtis C., J Curriculum Studies, 2005, volume 37, number 5, pages 525–559

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ZeroSum Ruler eBook!December 5, 2010

An eBook, complete with a ZeroSum Ruler cut-out, may be coming soon to CurrClick.com!

In the meantime, you can download a ZeroSum Ruler eBook and cut-out for \$4.00 through the ”Buy Now” button below, hosted by PayLoadz.com and PayPal…

Easy Factoring Trinomials…by grouping!November 27, 2010

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When I was a kid in high school, I remember trying seemingly endless combinations of numbers that would factor each assigned trinomial.  Well, you can kiss those hours of work good-bye!  Factoring by grouping is not only faster, it’s SIMPLE!  Just a few steps lie between you and complete trinomial factoring success…

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Graduate Thesis on… Negative Numbers?November 22, 2010

My thesis is a study of the long-term effects the ZeroSum ruler has on eleventh grade student understanding of negative integers.  By eleventh grade, students should easily be able to answer “-22 + 5 =”, but on a diagnostic test given to 57 students, 40.35% of the students answered this problem incorrectly.  Why does this matter?  It matters because it shows that students did not learn the relationship between negative and positive numbers in elementary or middle school.  By the time they get to me in eleventh grade and need to be fluent in equation manipulation, answering “-22 + 5 = -27″ is a real problem.

My thesis was set up the following way:

1: Diagnostic test: eight simple sums and differences of integers  (ie: ’22 + 5=”) without a ZeroSum ruler or calculator

2: Introduction to the ZeroSum ruler with examples

3: Three activities, spaced out over 2 weeks,  using the ZeroSum ruler

4: A post test within days of the last activity (no ZeroSum ruler or calculator)

5: A delayed retention test one month after the last activity (no ZeroSum ruler or calculator)

Because the attendance rates of students in Boston Public Schools is not the best, especially by the 11th and 12th grades,  a subgroup of 31 students was identified who took the diagnostic test, participated in at least 2 of the 3 activities with the ZeroSum ruler, took the post test, and took the delayed retention test.  The data shows a 62% decrease in student error from the diagnostic test to the delayed retention test.  These results indicate that the ZeroSum ruler works to improve student comprehension long-term even without the ruler.

Pretty exciting stuff.

Awesome Euclid and his AlgorithmNovember 19, 2010

One of my favorite things that I learned while in graduate school for math education was the Euclidean Algorithm for finding the Greatest Common Factor of two numbers.  If you click on the  picture to the left, you’ll get to a very informative YouTube video on the Algorithm.  It’s a bit boring, but very educational, and it shows exactly how to go about using Euclid’s method to find the biggest number that divides into two numbers.

(The screenshot to the left will bring you to the YouTube video on the Euclidean Algorithm)

The alternative, but mainstream, way using factor trees and circling primes always confused my students.  “Do I count the 3 twice since I circled it as a factor in both 81 and 57?”

If Euclid’s method was the mainstreamed one, math would be a lot more interesting and one more confusing topic could be checked off the list.  Euclid, you rock!

(The screenshot here of the kids is a funny video about Euclid and his algorithm)

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