Math 506 by Mark Cunha

"Invert and Multiply" - Don't Teach It

mcunha4281 — 2013-01-30 00:38:40 UTC

The old "skip, switch, and flip" rule, as I learned it, is simply a traditional algorithm. It wasn't until I became a teacher that I actually took the time to "learn" why it works when dividing fractions. Taking the time to have students invent their own strategies, or at least discuss as a class, different methods of dividing by fractions could prove very beneficial to a student's overall understanding of the concept.

Number Sense and Fractions

mcunha4281 — 2013-01-30 00:54:43 UTC

My greatest fear is the unknown. For many students, fractions (or mathematics in general) are the unknown. They get so wrapped up in "the formula" that they really don't have a clue what they are actually figuring out. Whenever possible, I like to have students discuss their solutions with each other. As the facilitator of these conversations, I always focus on the meaning of the mathematics. Asking questions like, "what does it mean to take 5/8 of a number?" can lead to more understanding than simply asking for an answer without any explanation.

Useful Activity #1

mcunha4281 — 2013-01-30 01:01:16 UTC

NCTM's Illuminations page has an applet game that has students adding fractions to move different buttons across the page. Various fractions from 1/10 to 1/2 are used. This also gives students an idea of equivalent fractions by stacking number lines,

http://illuminations.nctm.org/ActivityDetail.aspx?ID=18

Fractions and Decimals

mcunha4281 — 2013-01-30 01:21:55 UTC

I know the focus of this week's discussion is fractions, but students having troubles with fractions also tend to misinterpret decimals. I often find that my high school students have difficulty determining the greater number when given two quantities like .035 and .04. By discussing how these decimals relate to the fractions 35/1000 and 4/100 (or 40/1000) respectively, these students seem to gain a better understanding of both the fractions and the decimals.

Useful Activity #2

2013-01-31 02:53:41 UTC

Have students bring in their favorite recipe. It must require fractional parts of some ingredients. Have them convert the recipe to serve 20.

Make Sense of Fractions

2013-01-31 02:57:07 UTC

Develop a classroom definition of what a fraction is. Make sure that all students understand it. Get students used to using the terms numerator and denominator, as opposed to the top and bottom.

Fractions as Division

2013-01-31 03:00:55 UTC

All students need to understand that a fraction represents a division problem.

"You Best Represent!"

2013-01-31 03:02:23 UTC

Represent fractions as decimals and percents.

Students need to understand the concept of these representations, as well as be able to perform the computations.