## Tuesday, January 26, 2010

### scribepost for January 26, 2010

Today in class, our assignment was to fill in section 4.3 in our fold ables. The title was, 'Percent of a Number'. Here is what we had to put into our fold ables:
First we had to add notes from the key ideas in page 141.

- You can use mental math strategies such as halving, doubling, and dividing by 10 to find the percents of some numbers.
- To calculate the percent of a number, write the percent as a decimal and then multiply by the number.
e.g. 12 1/2 % of 150 = 0.125x50 = 6.25

After that, in the same box, we had to do the 'Communicate the Ideas' #'s 1 and 2.

1. a) 300% of 40 -

300% of 40 is 120.

b) 0.5% of 120 -
100%/100=1%
120/100=1.2

1%/2=0.5%
1.2/2=0.6
/= divided by
0.5% of 120 is o.6

c) 10 1/2 % of 80 -
100%/10=10%
80/10=8
10%/10=1%
1%/2=0.5%
8/10=0.8
0.8/2=0.4
10%+0.5=10 1/2 %
8+0.4=8.4
10 1/2 % of 80 is 8.4

2. 6% of 120 -

FIRST WAY:
100%/100 = 1%
120/100 = 1.2

1% x 6 = 6%

1.2 x 6 = 7.2

6% of 120 is 7.2

SECOND WAY:

I got 16.6 by, dividing 100 by 6.
To be honest, i had to use a calculator for dividing 120 by 16.6 to make sure 7.2 was right.

Lastly, we had to show a way to solve these percents:

10% - divide 100 by 10.
5% - divide 100 by 20.
25% - divide 100 by 4.
1% - divide 100 by 100.
0.5% -
divide 100 by 100, then by 2.

I apologize if it's late, I forgot about it.

### Owen's late Scribepost

Today, I was assigned to do questions 3 and 4 on page 142

3.Use mental math to determine the following:
A. 300% of 2000
2000=100% 100 x 3 = 300
2000 x 3 = 6000

B. 1/4% of 60
1% of 60 is 0.6

C. 0.1% of 40
1 divided by 100 = 0.1
1 divide by 40 = 0.025

0.1% og 40 is 0.025
4.
A. 20% of 60
If you divide 100% by 5 you will get 20%.
If you divide 60 by 5 you will get 12.

B. 250% of 400
200% of 400 is 800 because 400 x 2 = 800
50% of 400 is 200 because 400 divided 2 = 200
Then, you just add 200 and 800 togethere to 1000

C. 10 1/2% of 100
1/2% of 100 is 5
10% of 100 is 10
10 + 5 = 15

## Monday, January 25, 2010

### Brendan's Scribepost for January 25, 2010

How would you find __% of 400 ?

I found 25% of 400 by dividing 400 by 4.
100/4=25%
400/4=100

I found 60% of 400 by dividing 400 by 10, and then multiplying 40 by 6.
100/10=10
10x6=60%
400/10=40
40x6=240

I found 37.5% of 400 by dividing 400 by 10, and then multiplying 40 by 3. I know that 7.5 is 75% of 10 so 7.5% and 30% make 37.5%.
100/10=10
10x3=30

10/4=2.5
2.5x3=7.5

30+7.5=37.5%
400/10=40
40x3=120

120/4=30
30x3=90

120+90=210

I found 130% of 400 by dividing 400 by 10, and then multiplying by 13.
100/10=10
10x13=130%
400/10=40
40x13=520

I found 0.25% of 400 by dividing 400 by 100, and then dividing 1 by 4.
100/100=1
1/4=0.25%
400/100=4
4/4=1

I found 600% of 400 by multiplying 400 by 6.
100x6=600%
400x6=2400

I found 0.15% of 400 by dividing 400 by 1000, and then multiplying 0.1 by 1.5.
100/1000=0.1
0.1x1.5=0.15
400/1000=0.4
0.4x1.5=1.6

I found 240% of 400 by dividing 400 by 10, and then multiplying 10 by 24.
100/10=10
10x24=240%
400/10=40
40x24=960

I found 7.5% of 400 by dividing 400 by 1000, and then multiplying 0.1 by 75.
100/1000=0.1
0.1x75=7.5
400/1000=0.4
0.4x75=30

My other video is not up here because it says that "Your HTML cannot be accepted: Tag is not closed: EMBED"

## Monday, January 18, 2010

### Larrisa's scribepost for Percents

HI EVERYBODY (:

Key Ideas :

Fractions, Decimals and percent can be used to represent numbers in various situations.

Percent can be written as fractions and as decimals :

examples : 1/2 % = 0.5%/100 = 0.005

150% = 150/100= 1.5 or 1/2
42 3/4% = 42.75% 42.75% = 42.75/100 = 0.4275

Show you know :

fraction to decimal to percent :

3/40 = 0.0075 = 75%
171/300 = 0.57 = 57%
88/50 = 1.76 = 176%

decimal to percent to fraction

0.0064x100 = 0.64%
0.64 x 100
-----
1000x 100

= 64 divide by 2 / 10 0000 divide by 2

32 /5000

16 /2500

8 /1250

percent to decimal to fraction:

750% 7.5 7 50/100 7 1/2
0.3 divided by 100 0.003 / 1000 3/100
12 3/4 divided by 100 1275 divided by 100 = 0.1275/ 1000 1275/1000 51=400

### Sharmaine's Scibe post for Jan. 18, 2010

4. Convert each fraction to a decimal and a percent.

A.) 1/250 = 0.004 B.) 81/200 = 0.405 C.) 7/5 = 1.4
0.004 x 100 = 0.4% 0.405 x 100 = 40.50% 1.4 x 100 = 140%

5. Rewrite each fraction as a decimal and a percent.

A.) 51/30 = 1.7 B.) 21/200 = 0.105 C.) 3/500 = 0.006
1.7 x 100 = 170% 0.105 x 100 = 10.5 % 0.006 x 100 = 0.6%

6. Convert each decimal to a percent and a fraction.

A.) 0.0072 x 100 = 0.72%

B.) 0,548 x 100 = 54.8%

C.) 3.45 x 100 = 345%

PLEASE CORRECT ME IF I'M WRONG

## Thursday, January 14, 2010

### Jamie's scribepost for January 14, 2010

For homework, this is what Harbeck asked us to do:
Those are the answers I got. This is how I got the answers:

Larrisa & I made a mistake in this video, because we skipped a step.

### Ammorn's Scribepost for January 13, 2010

Question 3
Shindi commented to a friend that "some percents would be easier to show if we shaded the parts that were not included in the percent." Explain what she means. Which percents are easier to show using Shindi's Method? Why?
I think that Shindi means that it would be easier because then you wouldn't have to colour in that much. The percents that are easier to show Shindi's method are the percents that are over 50% because then all you have to colour are the other squares which is less than the percent.

Question 7
Represent the percent in each statement on a grid.
a) Attendance at the fall fair increased by 3.2% this year.
b) The average mass of a Singapura cat is about 0.13% of the mass of a Siberian tiger.
c) The length of the Yukon River is about 230% of the length of the Frasier River.
I still have to upload the pictures.

Question 10
Why might a scientist studying water pollution work with percents less than one?
A scientist might work with percents less than one because he might need to compare the measurement of something with a size less than 1%.

Question 15
Show how hundred grid(s) could be used to represent a very small percent, such as 0.000 0125%.
I still have to upload the pictures ..

## Wednesday, January 13, 2010

### Scribepost for January 13 , 2010 .

My scribepost will be answering questions 1 , 5 , 12 and 13 .

1. Use hundred grids and words to describe the similarities and differences between a percent less than 1%, a percent between 1% and 100%, and a percent greater than 100 %.

similarities are :

- it's still out of 100 .

- it can be shown on a hundred grid .

differences are :

- a percent less than 1 % is a decimal , it can't be a whole number .

5. What percent is represented by each diagram if a completely shaded grid represents 100%?

a ) 3/8 % out of 100

b) 125.5 % out of 100 .

c) 282 % out of 100 .

12. A 250-mL glass of milk contains 30% of the recommended daily value of calcium.Use a hundred grid to show how many glasses of milk you would need to drink to get 100% of the daily value of calcium .

So you would have to drink 833.3-> mL of milk to get 100 % calcium .

13. a) Use a calculator to convert 1/3 to a decimal. How could 1/3% be shown
using a hundred grid .

1/3 converted to a decimal is 0.3 repeated . x it by 100 gives you 33.3 repeated . So you would have to shade in 33 squares and a little part of another square .

b) Why are percents involving repeating decimals sometimes diffi cult to show on a hundred grid?

It's difficult to show it on the hundred grid because it's using a decimal place instead of a whole number . It's harder to estimate .

### April's scribepost for January 13th.

Today in class, we were assigned to do numbers 4-16 (and math link) on pages 128-129. Here are numbers 4, 8, 9, and 16.
a) 112 % b) 2/10 % c) 85 1/3 %

a) 3 b) 5 c) 12

Two examples where a percent greater than a hundred could be a glass of water compared to a whole jug, and the amount of snow in Winnipeg compared to the amount of snow in Calgary.

a) 1.7 % b) 130 %

c)

## Tuesday, January 12, 2010

### Scribepost for January 12, 2010

Hi everybody this is Jex explaining what we did today.
So today we corrected the fractions that we had to figure out in percents.

So these are the fractions :

So for Homework we have to define what a percent is.

Percent means out of 100 and is another way of
saying hundredths.

For example:

Our other homework was to do the show you know question.

I think this is all we did. Please comment and tell me what I did wrong and what I missed.

This blog was done by

Yours Truly

Jex

## Thursday, January 7, 2010

### scribepost for january 6 , 09

7. what is the height of the wheel chair ramp?give your answer to the nearest tenth of a centimetre .
c squared - b squared = a squared
80 squared - 79 squared = a squared
(80x80)- (79x79)= a squared
6400- 6241 = a squared
159 = a squared
square roots of 159 = square roots of a squared
a squared = 12.6cm
the wheelchair ramp would be 12.6cm tall

### Scribepost for January 7 , 2010 .

Sorry if some other person did this question already , but anyways here you go :)

page 110 .

# 3. Walter walks across a rectangular field in a diagonal line . Maria walks around two sides of the field . They meet at the opposite corner .

a) How far did Maria walk ?
120m + 300m = 420m . Maria walked 420m .

b) How far did Walter walk ? Express your answer to the nearest meter .

a2 + b2 = c2
3002m + 1202m = c2
( 300 x 300 ) + ( 120 x 120 ) = c2
90 000 + 240 = c2
c2 = 90 240 SQUARED .
c2 = 300.3m .

c ) Who walked farther ? By how much ?
Maria walked farther by 119.7 m .

there you go , please comment !

## Wednesday, January 6, 2010

### Connor's Scribepost for January 6, 2010

Hello I'm Connor, I am going to be showing the class how I did question 7.

Numero 7 =)

What is the height of the wheelchair ramp? Answer the question to the nearest tenth of a centimeter.

So the height of the ramp is 12.6 cm tall.

### Argie's Scribepost for Jan 6 2010

Hi my name is Argie, I had to do a scribepost and I chose question 4 on page 110.

4) Find the height of the pole where the guy wire is attached, round to the nearest tenth of a meter.

c² - a² = b²

10² - 2² = b²

10x10 - 2x2 = b²

100 - 4 = b²

96 = b²

√96 = √b²

9.7m = b

The height of the pole would be 9.7m.

### Mary Jane's Scribepost for January 6, 2010

I chose to do my scribe post on question number 14 on page 113.

Find the missing side length of each triangle.

a) a² + b² = c²
12² + 5² = c²
(12x12) + (5x5) = c²
144 + 25 = c²
169 = c²
√169 = √c²
13 = c

The length of c also known d is 13m.

b) c² - a² = b²
15² - 9² = b²
(15x15) - (9x9) = b²
225 - 81 = b²
144 = b²
√144 = √b²
12 = b

The length of b also known as v is 12cm.

REMINDER: study for the quiz tomorrow!
Tip: Do the practice questions in the math links. You could go to mytextbook.ca to find these questions.

### Gilbert Scribepost for January 6 2009

OK today in class Mr. Harbeck told the people who didn't do a scribe yet to pick a question and do one scribe.
OK so I chose number 7

7.What is the height of the wheelchair ramp? Give your answer to the nearest tenth of a centimeter.
Formula
c² - b² = a²
80² - 79² = a²
(80x80) - (79-79) = a²
6400 - 6241 = a²
159 = a²
√159 = √a²
12.6cm= a

Simple sentence answer- The height of the wheel chair ramp would be 12.6 cm high

### Scribepost for January 6th 2010

The question I chose to do is number 4 from page 110.

You want to find out the height of the pole where the guy wire is attached, to the nearest tenth of a meter.

The triangle isn't labeled as A,B,or C, my mistake.

c²-b²=a²
10²-2²=a²
(10x10)-(2x2)=a²
100-4=a²
96=a²
√96=√a²
9.8=a

### Scribepost for January 6, 2010

Today in class Mr.Harbeck told us to choose any question from 110-113 so I am doing question 6~!

You are asked to check the design plans for a baseball diamond. Is the triangle a right triangle? Explain.

I don't think its a right triangle because on either side of the baseball diamond its still not a right triangle.

P.S I know that you don't get this but the thing is that without a picture you still wont know so thats why I don't know how to rotate a picture in paint!     D:!

### Celdrick's Scribepost for January 6 2009

Hello.... Today in class all of the people who didn't scribble had to do one question and do a scribe about it.
(sorry my computer won't let me add colors for the letters)

I chose question 7.

7. What is the height of
the wheelchair ramp?
the nearest tenth of a centimetre.

First I did the formula.

Simple sentence answer: The height of the wheel chair ramp would be 12.6 cm high

Don't forget to

C
Co
Com
Comm
Comme
Commen
Comment

### Scribepost For January 6 2009

Today Mr. Harbeck said that if we haven't scribe yet we should pick a question. Here is question number 7.

7. What is the height of
the wheelchair ramp?
the nearest tenth of a centimetre.
c² - b² = a²
80² - 79² = a²
(80x80) - (79-79) = a²
6400 - 6241 = a²
159 = a²
√159 = √a²
12.6cm= a
The wheelchair ramp would be 12.6 cm tall.

### Elaine's Scribepost for January 6, 2009

For my scribepost, I chose to do question 7.

#7)
What is the height of the wheelchair ramp? Give

After I got my answer, I round it to the nearest tenth of a centimeter.

The height is 12.6 cm.

### Scribepost for January 6, 2010

Shahriar knows that the size of a computer monitor is based on the lenght of the diagonal on the screen. He thinks that the diagonal is not as large as the ad says. Is he correct? Explain.

a squared+b squared = c squared

25 square+3o squared = c squared

(25x25)+(30x30) = c squared

625+900=

1525= c squared

He is correct because the right lenght is 39 cm.

### Scribepost for January 6, 2010

Hi everybody. 'Im Jex and today we had to work on pages 109-113 to help us do good on the quiz . So I'm doing question 14.

Find the missing side length of each triangle.

Don't Forget to Study for the quiz tomorrow.