Hi. I've been lurking for a couple years, and finally registered because I hate these books so much that I had to reply. "Math Makes Sense" is awful, especially for gifted kids. I think it and books like it are why Canadian math scores are declining.
Our kids (both gifted) are in a small private school which switched to Math Makes Sense last year in order to better align with the Ontario curriculum. They largely abandoned it in October of this year because teachers, parents and students hated it. They're still using it for a few specific subjects, unfortunately.
DS11 is in grade 8 math. Last year, he and his teacher negotiated that he could skip some of the stupid tools like "algebra blocks" and also skip a lot of the "explain your answer" questions.
DD8 is in grade 4. In September/October, she brought the workbook home for homework and it was full of ambiguous questions and inefficient methods. She was starting to hate math and feel she was bad at it. (She isn't.) I am good at math and there were times when I struggled to help her, not because I couldn't understand it, but out of intense frustration with the book and its methods.
She had the textbook home over the weekend to study for a test and I flipped through it. There are lots (maybe average of 8 per page?) of colourful pictures and graphics, which I find distracting. However, I'm more concerned with the ambiguous questions, stupid questions and inefficient methods.
Here are some examples from the books:
1. Which is greater? An hour or 35 minutes? Why? (Valid question, I suppose, but it's wasting her time to answer why. And there's LOTS of explaining your answers in these books.)
2. Suzy is making punch for a party, one glass per person. The ingredients include 500mL of orange juice, 500mL of cranberry juice, 100mL of grenadine, 75mL of something else and 2L of gingerale. How many people are coming to the party?
(So, we can add the volumes to get 3.175L, but we're never told how big the glass is. Are we to assume that all glasses are 250mL? Or are multiple answers correct?)
3. Estimating. The question was 749-263. The instruction was "Use rounding to estimate each difference." DD calculated 750-250 in her head = 500, which is a decent estimate, 14 off the correct answer of 486. It was marked wrong. As far as I could tell from the examples, the "correct" answers are either 700-300=400 or 749-300=449, both, obviously, farther away from the correct answer.
BTW, 300 is a "friendly number". 299 is not.
4. In addition to such concepts as "friendly numbers" and "algebra blocks", DD was taught to multiply using a matrix. For example, for 24x67, she'd draw a 3x3 cube, entering 20 and 4, and 60 and 7. Then she'd have to calculate 20x60, 20x7, 4x60, 4x7 and then add it all up. It works, but it's very inefficient.
Sorry for going on and on. In my opinion, books like this are directly responsible for Ontario's declining math scores, increasing numbers of tutoring facilities, and petitions to improve math education. Avoid it if you possibly can.
