Friday, March 26, 2010

Math problems of the week: 5th grade Investigations vs. Singapore Math

Introductory division problems:

 From the end of 5th grade Investigations

 From the beginning of 5th grade Singapore Math

Niels Henrik Abel said...

Boy, I must be dense - how are the "two ways" indicated by Investigations supposed to help anyone, let alone a 5th grader, solve those division exercises? Seems way too obtuse, in my opinion. And they're concerned about turning kids off to math? Looks like they've found a way to do precisely that.

LexAequitas said...

Errr, ahhhh..... what?!?!

That's just bizarre. On being presented with something like "2000/42" I'm not going to try to start thinking of weird intermediary numbers like 840. The only way you would get to 840 as a number is if you first multiplied 42 *10, and then doubled the result.

1crosbycat said...

My son is in 5th using enVisionMATH, so I looked at his online textbook. Chapter 5: Dividing by 2-Digit Divisors progresses from mental math, using compatible numbers ot estimate, 1 digit quotient using multiples of 10 as divisors, 2-digit quotients where you first must estimate using compatible numbers. Finally we get to using a 4-digit dividend and a 2-digit divisor and they say "estimate first. Then use a calculator to solve." That's it - no more division in the book contents. So the hardest problem I see is: 4328/93 (there was one other like this).

Robyn Spoon said...

I just wanted to say thank you for summing up all of the concerns I have had about reform math. I would love for you to evaluate/consider higher levels of text books. For example, what alternatives are there to CPM Algebra 1. My very left-brain child is using this text as a 7th grader and for the first time in her academic life is confused about her math work. We recently had to hire a tutor. She aced pre-algebra (traditional text) and was math bowl captain as a 6th grader. Our district is reviewing math text books for the next series and I am concerned about the possibility of more CPM.