Lesson 5.9 (during visit to Redding)

We learned many things about Growing with Mathematics on our visit to Redding yesterday (1/9/07). We watched lesson 5.8 and 5.9. Below is a description of lesson 5.9.

During lesson 5.9 (Solving Addition Problems), there was a bit of confusion. The lesson itself was not very difficult for children to understand. However, the teacher attempts to lead the children to discover patterns in addition number sentences. This lesson is really asking the teacher to teach the children a strategy for adding numbers.

On discussion book page 38, the numbers are presented in a child-friendly way. Students are shown a page which provides the scenario that they will be buying toy dinosaurs. The possible costs of the dinosaurs are: 22, 19, 20, 18, 30, 29, 31, 21 cents. The first thing the lesson wants the students to notice is that these numbers, when put onto a number line, are in clusters around either 20 or 30. Then the lesson wants student to recognize the following pattern with numbers clustered around a number:

If 20 + 20 = 40 and I add 1 to the first 20 (21) and take away 1 from the second 20 (19), I still get 40 when I add the two numbers together. The pattern looks like this:

20 + 20 = 40
21 + 19 = 40
22 + 19 = 40

There are many other problems on the discussion book page all of which are related to this concept, though each different question asks children to think about and manipulate the provided numbers in a different way.

Before you get to the student book pages, make sure you do all of the questions on Discussion book page 38 since the way questions are asked on the student book page directly relate to the discussion book page.

Suggestion: Do the whole-group lesson one day. Since this will take a lot of time, do the student book page the following day at the beginning of class. I would not suggest sending this page home because there will probably be confusion.

Lesson 5.8 (during visit to Redding)

We learned many things about Growing with Mathematics on our visit to Redding yesterday (1/9/07). We watched lesson 5.8 and 5.9. Below is a description of lesson 5.8.

During lesson 5.8 (Adding Two-Digit Numbers), the teacher did a great job of showing the students that there were MANY ways to solve the given addition problems. This lesson clearly built upon prior knowledge of addition.

The part of the lesson that I liked the best was that when the teacher asked for student answers, she had the students give the answer and then each student had to talk about the strategy used and the steps followed to solve the problem. The students in her class used at least six different strategies for solving two-digit addition problems. Some examples were:

- Hundreds chart
- Number Line
- Adding columns from right to left
- Adding columns from left to right
- Base-ten Blocks
- Coins... this is the one that I found most interesting. One student asked the teacher if she could add 52 and 35 together using coins. I had never seen a student do this before. The student drew the two quarters and two pennies for the 52 and drew a quarter and a dime for the 35. She then added the three quarters together and knew this was 75. Then she added on the dime (85) then added the two pennies for a total of 87.

This student truly exhibited a great number sense.