## Saturday, September 30, 2006

### Time for Scribes

Mr. Kuropatwa introduced me to the world of Scribe Posts. It is an essential part of the Grade 8 Math Classroom. You will be expected to write one scribe post every 30 classes or about 4 a year. That doesn't sound like to much does it.

A Scribe post is

The assignment is simply to post a brief summary of what happened in class each day. A different student is responsible for the daily scribe post and they end their post by choosing the next scribe. The first scribe is a volunteer. The teacher's daily involvement is limited to updating a post called The Scribe List which is at the top of the links list in the sidebar of the class's blog.

To complete a scribe post the student must

Write a brief summary of what we learned in class today. Include enough detail so that someone who was away sick, or missed class for any other reason, can catch up on what they missed. Over the course of the semester, the scribe posts will grow into the textbook for the course; written by students for students. Remember that as each of you write your scribe posts. Ask yourself: "Is this good enough for our textbook? Would a graphic or other example(s) help illustrate what we learned?" And remember, you have a global audience, impress them.

Here are examples of good scribe posts Pythagoras Scribe One Day In Math Algebra Masterpiece

Here are some scribe posts that have made The Scribe Post Hall of Fame.

When you are done your scribe post choose another student to be the scribe and label your post scribepost.

## Tuesday, September 26, 2006

### Question #5

Question 5
A) 33, 18, 40, 26, 29, 20, 30
18+20+26+29+30+33+40= 28
7
Mean 28, Median 29, Mode no mode, Range 22.
B) 20, 50, 20, 50, 17, 15, 25, 50, 25, 15
15+15+17+20+20+25+25+50+50+50= 28.7
10
Mean 28.7, Median 22.5, Mode 50, Range 35.
C) 15, 20, 80, 75, 5, 50
5+15+20+50+75+80= 40.8
6
Mean 40.8, Median 35, Mode no mode, Range75.
D)
16, 40, 44, 16, 40, 40, 80, 17, 64, 64, 100
16+16+17+40+40+40+44+64+64+80+100= 47.4
11
Mean 47.4, Median 40, Mode 40, Range 84.

I got the answer by adding the sum of all data. Then I divided how much information. Then you get the answer. Which is the MEAN, the MODE is the number that shows up the most, the MEDIAN is the number in the middle, and the RANGE is the first (smallest) number subtracted from the last (biggest) number.

## Monday, September 25, 2006

### Bill's History Marks!

2. Bill's history marks are: 72, 66, 65, 73, 71, 69, 68, 72.
Find the mean, mode, median and range.
Mean:
65+66+68+69+71+72+72+73= 556/8= 69.5

Mode- 72
Median- 65, 66, 68, 69, 71, 72, 72, 73= 69+71= 140/2= 70
Range- 73-65= 8

A) If he scores 91 on the next test, which measure of central tendency will be most affected? Explain.
Mean:
65+66+68+69+71+72+72+73+91= 647/9 = 71.8
or
556+91= 71.8

Mode- 72
Median- 65, 66, 68, 69, 71, 72, 72, 73, 91= 71 is the median
Range- 91-65= 26

The most affected measure of central tendency will be the range because it got higher by 18.

B) If he scores 66 on the next test, Which measure of central tendency will be most affected? Explain.
Mean:
65, 66, 66, 68, 69, 71, 72, 72, 73= 622/9= 69.1

Mode- 66 , 72
Median- 65, 66, 66, 68, 69, 71, 72, 72, 73= 69 is the median
Range- 73-65= 8

The most affected measure of central tendency will be the mode because there are more than one mode- 66 and 72.

Please feel free to comment on this post for any errors or suggestions.

### Question 3 on page 1 of the Pretest sheet

Ok, it's my job to do the heading up above so here are the questions:

3. Find the Value of x in the data.
10, 12, 6, 6, 14, x, 8, 10, 12, 12, 8, 14
A) If the mean is 10.

B) If the mode is 12.
C) If the median is 11.
Is there more than one possible answer for each question?

6, 6, 8, 8, (this is the number that replaces the x) 8, 10, 10, 12, 12, 12, 14, 14.

If you all them all up, you get 120. The we divide it by 12 to get the mean of 10. So it looks like this:

120
---- = 10
2
Let's move on now to 1b. If the mode is 12, the number that has to show up is 12. Here's one way of doing it.

6, 6, 8, 8, 10, 10,(this is the number that replaces the x) 12, 12, 12, 12, 14, 14.

When you match them all up, the middle number should be 12. If you want a short-cut, here's the faster answer. As long as the number has equal or greater value, it is considered correct.

Yay! I'm almost done. Here's the final answer, well almost, ok 2nd last answer. This is the answer to question 1c.

For me, I just repeated the same numbers as I got above. I'll put them down again to help.

6, 6, 8, 8, 10, 10, 12, 12, 12, 12, 14, 14.

When you match them up, you should get 2 middle numbers, 10 and 12. When you add them up, your sum should be 22. You then divide 22 by 11 to get your median 11. I'll do this in math form for you people who dont get a word I typed down. It should look like this.

10+11= 22

22
--- = 11
2

Last question. It says this: Is there more than one possible answer for each question?

The answer is yes, there can be more then 1 possible answer for each question. How? Let's see. In the math world 1 simple word problem can have at least a hundred different ways of answering it. But most of us don't take the time to search, we just do the question the way we were taught. If we took more time, we would begin to see many different ways of doing a question and geting a different answer or answers. Well, I've said enough. Ok. I'm done this thing.

Till next time:
Meldee

### Math Pre-test 2

State 7 prices, where the median is \$3.00, the highest price is \$20.00 and the lowest price is \$1.00.

1.00, 2.00, 2.00, 3.00, 7.00, 15.00, 20.00

## Friday, September 22, 2006

### Measures of Central Tendency Pretest 2

Here is the worksheet I provided you on Friday. Please answer the questions in a comment. You can also ask questions about anything you need help on here.

Good Luck

1. State 7 prices, where the median is \$3.00, the highest price is \$20.00 and the lowest price is \$1.00.
2. The mean mark on 4 tests is 78%. What mark is needed on the next test to increase the mean to 80%?

3. Julie buys a book, a game, a puzzle, and a piece of computer software at the book fair. The computer software cost \$10. Julie claims that the average price of the items she bought is \$2.50. Can she be correct? Why or Why not.

4.
Mr. Thompson gave a test to six students who were absent. The highest score was 93 and the lowest score was 65. The mean of the test scores was 79. Create a list of six test scores that satisfy these conditions. Explain why your test scores satisfy these conditions.

5.
Find the measures of central tendency for the following data sets:

A) 33, 18, 40, 26, 29, 20, 30
B) 20, 50, 20, 50, 17, 15, 25, 50, 25, 15
C) 15, 20, 80, 75, 5, 50
D) 16, 40, 44, 16, 40, 40, 80, 17, 64, 64, 100

### Measures of Central Tendency Pretest 1

Measures of Central Tendency Pretest

Here is the worksheet I provided you on Thursday. Please answer the questions in a comment. You can also ask questions about anything you need help on here.

Good Luck

1.Find a set of values to fit these conditions.

A) Five numbers with a mean of 7 and a median of 5.
B) Seven Numbers with a mode of 8 and a median of 6.
C) Seven numbers with a mode of 10 and a mean of 9.

2. Bill's history marks are: 72, 66, 65, 73, 71, 69, 68, 72.
Find the mean, mode, median and range.

A)
If he scores 91 on the next test, which measure of central tendency will be most affected? Explain.

B) If he scores 66 on the next test, Which measure of central tendency will be most affected? Explain.

3. Find the Value of x in the data.

10, 12, 6, 6, 14, x, 8, 10, 12, 12, 8, 14

A) If the mean is 10.
B) If the mode is 12.

C) If the median is 11.

Is there more than one possible answer for each question?

## Tuesday, September 19, 2006

Here are the instructions for you to get your blogger account active.

A) Get a google account. You can do this from either blogger or google itself.

B. You will use this account to access betablogger.

At Blogger you need to create a blog. Call it any thing and follow the steps.

Create 1 post and publish it.

***** Keep this window open for the next steps*****

Open a new browser window (control n)

Find the email I sent inviting you to the blog.

## Tuesday, September 12, 2006

### This Is My Life

A Graph of My Life

Estimate the amount of time you spend each weekday doing the following activities:

Playing
Attending school
Doing homework
Sleeping
Watching television
Other activities

Make a graph that represents your estimates. Please remember that there are 24 hours in a day!

This Assignment is due Thursday, September 14.

Mr. Harbeck

## Sunday, September 10, 2006

### Why we Blog

As I asked you in class "How many of you blog?" Most of you put up your hands because of your experience with Mr. Reece last year. Many of you also indicated that it was not you favorite activity during math class. I hope to change that this year. It is important to know that times are changing. The world you know now will be different by the time you enter highschool, and that world will change by the time you are ready to enter Highschool.

K. Fisch a teacher in Colorado created this powerpoint presentation for his students. It demonstrates how the world is changing. It is a remarkable presentation.

Did You Know

In your journals or as a comment I would like you to tell me what you are feeling after this presentation. Mr. Kuropatwa from Danial Mac asked his grade 11 and 12 students these questions:

• What surprised you the most? Why was it surprising?

• Did you learn anything? If so, what?

• As you think about it now, does this change the way you think about school, learning or the purpose of getting an education? Is there anything you want to do differently related to school this year?

• What Shift is happening?

Mr. Harbeck

## Friday, September 08, 2006

### Mr. Barksalot's Bath Graph

Welcome to your Math Blog. It is a place for you to post answers to questions and to communicate to the world about what happens in 8-17 Math. I would like you to leave a comment answering the following question. Some of this work will have to be done in your math journal. The bold print can be left as a comment.

Bobby fills a sink with enough water to wash his dog Mr. Barksalot. He then puts Mr. Barksalot in the sink and washes him. After he is finished he takes Mr. Barksalot out of the sink. Then he drains the sink.

Draw a graph that represents the level of water in the sink from the time paula started to fill the tub until the tub was empty. Clearly label your graph.

Explain what the graph should look like in a comment on this post AND on the back of your graph.

Mr. Harbeck

## Wednesday, September 06, 2006

### Welcome 8-16

In the coming days you will be given access to a wonderful tool. This blogsite is designed to be helpful and interactive. How much work you place on doing your posts and assignments will determine the greatness of the site.

Last year this is what 8-16 created. Let's do it again.

Mr. H