Review of 6th Grade CMP Text by Betty Tsang
Mainly a game book but unfortunately, a boring game book with factors. The student material probably is very boring for a regular 6th grader who learn most of these materials in 5th grade. For a curriculum that stresses on real world problems, most of the problems are not real life problems. For example, there are exercises to discover abundant, deficit and perfect number which are interesting numbers but have no application in life -- most scientists and mathematicians have not heard about them. The last chapter on the locker problem is interesting. However, I wonder how many 6th graders figure that problem out by discovery alone.
Bits and Pieces I: Understanding Rational Number
The only good news about this book is that the kids get beyond clock math used in 5th grade. Instead of clock, the students use fraction strip! Again, most of the materials described here about fractions, decimals and percentage are so simple minded, a competent 6th grader would have known the material already. Again some exercises I see illustrate problem regarding the unstructure and disorganized way about CMP. For example, Problems to extract fraction of shaded area (half of a circle inside a square with twice of the radius) is impossible for students who have not been exposed to circles. I know for sure that 5th graders under current system have not learned about circles yet. Reform math does not believe in sequential learning which is the beauty of mathematics.
Bits and Pices II: Using Rational NumberBits and Pices II: Using Rational Number
It was my daughter's experience with this unit that I started tutoring her at home. She was an A student and was in 7th grade. She was completely confused by the way CMP introduced fractions, decimals and percentages. She was frustrated by the tricks that she "discovered" which did not work in more general cases. Obviously she was not taught about formulas to convert one to the other. A lot of students have problems learning addition and subtraction of fractions using this unit. My daughter already knew manipulation including division of fraction very well by the time she encountered this book.
Shapes and Designs: Two-Dunebsuibak Geometry
After 6 weeks of playing around with polygons and triangles in 5th grade, I don't see any point of playing some more without really learning how to measure angles with protractors (most common and cheap tools available in book stores). It is pathetic to teach area of rectangle, squares and triangles probably in 6th grade. The last chapter on logo programming looks interesting but I have no knowledge of this to judge -- the commands seem to introduce the students to actual angles and may be useful.
Covering and Surrounding : Two-dimension Measurement
Again, I prefer to learn about calculations of perimeters and areas the old fraction way by instruction with illustration than to learn by discovery. Discovering pi by cutting and pasting of circles is a waste of time. One popular eay to discover pi in other reform books is to measure circumference and diameter. pi=circumference/diameter. It is much easier. Even so, it took my daughter nearly two hours one evening to do such activity. What is wrong with just remembering pi as 3.1416 and to show that pi is less than 4.
How Likely is it: Probability
Most of these concepts of probability of getting head or tails by flipping coins, getting one of the number in tossing dice are so obvious to some kids, they would resent some of the "tedius" experiments.
Data about us: Statistics
The book seems o.k. except maybe the time required to finish it. I do have reservation about 2-d scatter plots. I am not sure how many students will get that when simple linear relation concept has not been introduced yet.
Ruins of Montarek: Spatial Visualization
Currently not in math curriculum but is one of the electives in 6th grade. I believe that is where CMP belongs.