Tuesday, May 31, 2011

Math prep

I've been working with the 11 year old, prepping her for the ISEE exam. I've come to realize that half the battle, or more, is finding the right materials. This was true of the boy's spelling as well. Once I found "All About Spelling" the rest was easy.

With math, the trick is to find as many problems as possible. Repetition and experience--practice to mastery, if you want to use the lingo--is the way and the light.

So, I've been hunting for good resources. I'm not exactly shocked that a Singapore Math workbook is currently my favorite. I've decided to work on ratios and proportions for a while, and this book:

has lots of good proportion problems just like the ones on the ISEE.

Of course, the more I look at these books (I worked through all the workbook the other day,) the more I realize how sloppy they are. Even the Singapore one has poorly worded questions and some flat-out wrong answers.

Poorly worded such as: You have a box of known dimensions, filled to height y with water. Rocks are added to bring the level up 10 cm. How has the volume of water changed? Well, of course, the water hasn't changed at all, you just added rocks.

Ann and Wilma share some apples and pears in the ratio 5:7.... Is the ratio the number of apples to pears? or is the ratio Ann's to Wilma's? I assumed the former, because it was closer to the modifying ratio. Unfortunately, they actually meant the ratio of Ann's to Wilma's fruit.

If Joe swam 33 laps on both days... Should that be 33 laps per day, for a total of 66 (which is what I assumed)? or should it be 33 combined on both days? The answer in the back of the book correlates with 33 laps total.

These are books that are republished regularly, you would think that they would fix the errors over time.

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