Fifth Grade - November 10th - 14th, 2008

Fifth graders begin their study of fractions this week. They will make fraction strips in order to look at equivalent fractions. They will explore the meaning of numerators and denominators and look at how the size of the denominator affects the size of the pieces being looked at. For example, would you rather have 1/2 of a candy bar or 1/3 of a candy bar. At first, it may seem like 1/3 is bigger because the 3 is bigger than the 2. However, when you cut one candy bar into 2 equal pieces and another candy bar into 3 equal pieces, each of the 2 pieces are bigger than each of the 3 pieces.

Fourth Grade - November 10th - 14th, 2008

Fourth graders will begin their geometry unit by studying the characteristics of polygons. They will look at shapes that are polygons and shapes that are not polygons. From their observations, students will decide what is true and untrue about polygons. Some characteristics of polygons include:

• It is a closed figure - there are no openings in the shape.
• It only has straight sides - there are no curves.
• The lengths of the sides don't have to be equal.
• It doesn't have to be a typical shape like a square or rectangle

Students will then extend their study to polygons with 3, 4, 5, 6, 7, 8, 9, 10, 11, and 12 sides.

Third Grade - November 10th - 14th, 2008

We had an interesting discussion with one of the homework problems last week. The challenge was to find 70 less than 231. It is always important to put a problem into a story context so that the numbers make sense. Imagine this problem as a student having 231 stickers and they give 70 away to their best friend. One way to solve this problem is by making the numbers easier to work with. Instead of having 231 stickers, imagine that you only have 230 stickers and you give away 70 of them. Now the problem becomes much more manageable. It can be thought of as 23 tens minus 7 tens which is 16 tens or 160. The question is what happened to that extra sticker. Do we have 161 or 159 stickers left over. Well, think of our story. I started with 231 stickers but I made the problem easier by changing it to 230 stickers. It is like I put the extra sticker in my pocket. After I gave away 70 of my stickers, I can pull the extra sticker out of my pocket, so now I have 161 stickers.

This week, students will look at a problem like this, but the extra sticker is being subtracted. instead of 231 - 70, think of the problem 230 - 71. Again, lets make the problem easier by solving 230 - 70 which is 160. So, what happened to the extra sticker? In this case, the extra sticker is being given away, so after I give away the 70 stickers I still have to give away one more. Instead of having 160 left over, I now have 159.

The general idea is that if 120 - 50 = 70, then 120 - 54 will be 4 less or 66. If 120 - 50 = 70, then 124 - 50 will be 4 more or 74.

Second Grade - November 10th - 14th, 2008

Second graders are beginning to solve problems with bigger numbers. One problem we will look at this week is 12 + 24. Here are a few strategies we expect kids will discover as they solve this problem:

• Adding in Groups - Some students will start at 12 and count by ones 24 times. This method will work, but it becomes inefficient with large numbers. We would like to see kids who can start at 12 and add 10 at a time instead of 1 at a time. 12 + 24 can be thought of as 12 + 10 + 10 + 4.
• Breaking the Numbers Apart - Students may see that they can break the numbers 12 and 24 into (10 + 2) and (20 + 4). Since we just studied that order does matter when adding, we can rearrange our numbers to be (10 + 20) + (2 + 4). Now students are adding the tens together and the ones together. 10 + 20 = 30 and 2 + 4 = 6, so 30 + 6 = 36.

First Grade - November 10th - 14th, 2008

First graders are working on addition and subtraction story problems. Students are learning how to show their work using pictures, words, and numbers. It is very important for students to be able to show or explain how they got their answer. We often hear young children say, "I just did it my brain." We are trying to move kids away from that answer to actually showing their work.

Here are some of the strategies our students have learned to add and subtract:

• Counting All - Students add 3 + 7 by counting 3, then counting 7, and then starting over again with 1 and counting all the way to 10. We would like to see students move away from this strategy when they feel more comfortable with numbers.
• Counting On - Students add 3 + 7 by counting 3, then counting on from 3 an additional 7 so that they get to 10.
• Counting Back - Students solve 9 - 4 by starting with 9 and counting back 4 so that they arrive at the answer of 5.
• Using Known Combinations - Students solve 6 + 8 by reasoning that if 6 + 6 = 12, then 6 + 8 must be two more than 12 which 14.

Fifth Grade - November 3rd - 7th, 2008

Fifth grade students are finishing up their unit on addition and subtraction. They are using the strategies they have already explored (see blog entry on October 22nd) to solve problems with larger numbers like 69,703 - 55,675.

Fifth graders will also be assessed on how well they know their division facts. Students should be able to solve 30 problems in about two minutes. Students who are not this proficient with their facts should practice at home.

Fourth Grade - November 3rd - 7th, 2008

4th graders are beginning a unit on 2-D geometry and measurement. This week we will study linear measurement using both the U.S. system and the Metric system. Students will identify objects they can use as benchmarks to help them estimate lengths. For example the length of a piece of notebook paper is about 1 foot. Students will explore rulers, yardsticks, and metersticks and use these tools to measure the length of the classroom and other objects. They will also explore the idea of perimeter and measure different items in the room. Finally, students will design a path in the school that is 100 feet long. Most students (and many adults) find it difficult to picture 100 feet. This will be an eye-opening experience.