charis' scribepost for January 26 2010

determine the percent of each number.
give you answer to the nearest hundredth.


5. A) 2/5 % of 325
0.004 of 325
0.004 x 325 = 1.3
how i got 0.004 :
divided 5 and 2 and got o.4 .


b) 15 1/4 % of 950
1525 of 950
0.1525 x 950 = 144.88
how i got 1525 :
divided 1 and 4 and got 0.25
so i put it together with the 15 .


c) 175% of 125.00
1.75 of 125.00
1.75 x 125.00 = 218.75


6. A) 5/8 % of 520
6.25 of 520
6.25 x 520 = 3250
how i got : 6.25
divide 8 and 5 and i got 6.25 .

b) 75 2/5 % of 200
7510 % of 200
7510 x 200 = 15020
how i got 7510 :
divide 8 and 5 and got 10 .

c) 250 % of 76.50
2.50 of 76.50
2.50 x 76.50 = 191.25

if i did something wrong , please comment . thank you (:

Giuseppe's questions for Jan 26 10

3. Use mental math to determine each of the following.

a) 300 % of 2000
100% of 2000 = 2000
300% of 2000 = 6000
To get 300%, you have to multiply the number by 3

b) 1 1/4 % of 60
1% of 60 = 0.6
0.25% of 60 = 0.15
0.6 + 0.15 = 0.75
I know that 1% of 60 is 0.6. So I divided that by 4 (to get 0.25%), and I got 0.15. I added them together and got 0.75

c) 0.1 % of 40
1% of 40 = 0.4
1% ÷ 10 = 0.1%
0.4 ÷ 10 = 0.04
First, I found 1% of 40. Then to get 0.1%, I divided 1% by 10. So that means I have to divide 0.4 by 10 to get 0.1% of 40

4. Use mental math to find the following.

a) 20 % of 60
100% of 60 = 60
100 ÷ 5 = 20
60 ÷ 5 = 12
To get 20% of a number, divide it by 5

b) 250 % of 400
100% of 400 = 400
100 × 2.5 = 250
400 × 2.5 = 1000
To get 250% multiply the number by 2.5

c) 10 1/2 % of 100
100

100% 100
10% 10
1% 1
0.5 0.5

10% + 0.5% = 10.5%
10 + 0.5 = 10.5
If you're trying to find a percent of a hundred, don't work so hard. The answer is the percent they're asking you to find.
Example: 45% of 100 = 45
32.256 % of 100 = 32.256

Hope this helps!!!!! Please comment if you have a question......even though I'm not gonna answer it

Kathleen's Scribepost for January 26,2010

Foldable.
4.3 Percent of a Number

Key Ideas:

• You can use mental math strategies such as halving, doubling and dividing by ten 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.

EXAMPLE:



How to FIND :

• 10% - divide by 10.
• 25% - divide by 4.
• 5% - divide by 20.
• 1% - divide by 100.
• 150% - divide by 2 then add the numbers.
• 0.5% - divide by 100 then divide by 2.

Communicate the Ideas.

1. Explain to a classmate how you could use mental math to find each of the following:








2. Describe two ways to find the 6% of 120.



OR







We have been using Ustream to record our percent work.

Alvin's Scribepost for January 19, 2010

For the past century, the north magnetic pole has been drifting across the Canadian Artic. Prior to the 1970's , the magnetic pole was drifting at an average speed of 10 km/year. Since the 1970's , the speed at which the magnetic pole has been drifting has increased to about 50 km/year. The circumference of Earth is approximately 40 000 km.

a) What percent is the current speed of the original speed ?

The Current speed is 50 km/year.
The original speed was 10km /year.

Now to get the percent you first must find the decimal, to do so you first divide 50 by 10 which will give you 5, there's your decimal.
Then you multiply your decimal by 100 so 5 x 100 = 500.
So then the answer is the current speed of the original speed is 500%.

b)The circumference of the earth is approximately 40 000 km. At 50 km/year, what percent of the earth's circumference will the pole drift in 1 year ?.

First we have to find the decimal so then we divide 50 by 40 000, the answer is 0.00125 now we multiply it by 100 to get the percent.
So 0.00125 x 100 = 0.125%
In one year the pole will drift 0.125% of the Earth's circumference

Scribepost for January 7, 2010 7:16 PM

I'm taking care of part 1. Which is Part 1 of your homework. :D

So, you go to mytextbook.ca and login. Go to Chapter 4 section 4.2: Representing Fractions, Decimals, and Percents. Scroll down to page 135 and look at Key Ideas.


You are going to copy that to your foldable, on the second flap 4.2 Fractions, Decimals, and Percents.

Open it up and copy on the top.

TO THE PERSON READING THIS: DO PART 2. YOU HAVE TO ANSWER 3 QUESTIONS FROM PAGE 135.

Kamille's Scribepost For January 14th, 2009

Today in class all we did was correct the questions from yesterday's class but when it was almost time to go we had homework .. and here it is.
















How got the answers was:
Fractions to Decimals - Numerator / Denominator
Decimals to Percents - Multiply the decimal by 100
Percents to Fractions - Divided 100 and then find the decimal place and then reduce if possible

Don't forget to comment below and at the Sargent Park math zone too :)
-- Kamille was here

John's Scribepost for January 13, 2010

Questions 2,6,11,14

Question 2:

A)You are asked to show a classmate how to use hundred grids to show

243%. How would you explain which squares need shading.

Answer:You would shade in 2 10x10 boxes and take another box and only shade in 43 boxes

And the fraction form is:

B) Explain how you would represent 25 1/4% on a grid:

Answer:You shade in 25 boxes and divide one box into 4 smaller boxes and shade only one of the smaller boxes.

Question 6:

Represent each percent on a grid.

A)125%

B)10 1/2%

C)0.4%

D)262%

E)7/8%

F)45.6%

Question 11:

The land area of Alberta is about 113% of the land area of Saskatchewan. Use hundred grids to show the land area of Saskatchewan.

Question 14:

A)If 200 squares were used instead of 100 squares to represent a 100%, how would you show 0.25%

B)If 400 squares were used instead of 100 squares to represent a 100%, how would you show 0.75%

-JOHN!

Jeric's ScribePost for January 13

For my scribe post I'm supposed to do questions 4, 8, 9, and 16.

Question 4:

a) 112 %

b)2/10 %

c) 85 1/3 %





Question 8:





a) 3
b)5
c)12

Question 9:

An example for a percent that is greater than 100% is for test marks that are 11 out of 10 because of bonus marks and math.

Question 16:


a) 1.7 %
b) 130 %
c)

Well I can't really show question c because I have to do it at home so yeah.

PEACE EASY GUYS !!!

Emmanuel's Scribepost for January 13

QUESTION 13:

13. a) Use a calculator to convert 1/3 to a decimal. How could 1/3% be shown using a hundred grid?
1/3 as a decimal would be 0.33333333...
This is how it would be shown on a graph:












b) Why are percents involving repeating decimals sometimes difficult to show on a hundred grid?
It is hard to show repeating decimals on graphs, because you would have to divide a single block into thousands or more!

QUESTION 12:
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.


Each GREEN area represents a glass of milk containing 30% of the recommended daily value of calcium. So if you drink 3 glasses, you get 90% of the RDVC. So the BLUE area at the bottom represents 1/3 of a 250mL glass. Which would be 10%, and give you your full 100% of RDVC!!



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




a) 0.3% or 3/10%




b)125.5% or 125 1/2


c)282%





QUESTION 1:

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%.

I couldn't find the answer

elijah's scribe post 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 whatshe means. Which percents are easier to show using Shindi’s method? Why?

I think wat shindi means is that if you have 86 % .. you can just shade in 14 squares and the non shaded side is representing the 86 %.










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 Fraser River.

Question 10:

Why might a scientist studying water pollution work with percents less than one ?

The scientist might have found out that the pollution is less than 1 % .

Question 15:

Show how hundred grid(s) could be used to represent a very small percent, such as 0.000 0125%.

10 squares in a 100 grid is 10 % ,
10 squares in a 1000 grid is 1 % ,
10 squares in a 10 000 grid is 0.1 %,
10 squares in 100 000 is 0.01 % ..


This is a 1000 grid, and the coloured part is 1% but if it was a 100 grid the percent would be 10 . But to get 0.000125 you would need a ten million grid square .





Please comment and correct me if I'm wrong.


For February 5 2010
Me,Sierra, Riemer, and Josh's math video

Converting Fractions, Decimals and Percents :

Jose's scribepost for January 12, 2010

PERCENTS:

Today in class, we started off by correcting the homework from yesterday. After that, Mr.Harbeck told us that we had to make a new foldable on understanding percent. First we labeled each fold and for the first one we had to define what a percent is, and a fractional percent.

PERCENT - Percent is an equivalent fraction out of 100, and its another way of saying hundredth.

FRACTIONAL PERCENT - A percent that includes some sort of percent. Some examples are 1/2 % , 5 6/8 % , 7 3/8 % and so on.

After we finished that, Mr.Harbeck assigned us to finish SHOW YOU KNOW on page 125 in the text book :

SHOWYOUKNOW pg 125 :

One completed shaded grid represents 100%. what percent does each diagram represent?



This picture represents 248%. Since there are 2 filled up grids which means that its 200%, the other grid has 48 shaded in so its 248%.









This picture is 0.25%. If one little square on the grid is not even filled up fully, then it must mean that its below one. Thats why it is 0.25%










This picture represents 74.8%. Since there are 73 little grid pieces all filled in, and 8/10 of another grid piece it would be 74.8%












Those were the things we did in class. Comment and tell me if i messed something up. josh

Sierra's Scribepost For January 11, 2010.

Percent is an equivalent fraction out of 100.

Percents can convert from

• Decimals
• Fractions
• Ratios

But, rate CANNOT be converted into a percent.
In everyday life, you can find percents on

• Sales or discount
• Test marks
• Probability of precipitation
• Currency
• Dairy products
• Interest
• Votes or survey
• Alcohol
• Taxes

Here are different ways to do a percent:















For homework, we had to convert the following fractions into a percent two different ways.

Vanessa's scribe post for January 5, 2010

Sorry its really, really, really late but here it is ...

QUESTION 4

Find the height of the pole where the guy wire is attached, to the nearest tenth of a metre.

c² - b² = a²

10² - 2² = a²
(10x10) - (2x2) = a²

100 - 4 = a²

96 = a²

√­­­­­­­­­­­¯96 = √­­­­­­­­­­­¯ a²
9.8 = a

The height of the pole is 9.8 metres.

Again I'm sorry that it's late. Hope I made you happy Harbeck !

Riemer's scribepost for January 5, 10

Question # 12 pg. 105

The hypotenuse of the triangle cuts the    circle in half. What is the diameter of

the circle? Express your answer to the 

nearest tenth of a centimetre.

                                               a²+b²=c²

                                               7²+5²=c²

                                               (7x7)+(5x5)=c²

                                               49+25=c²

                                               √74=√c²

                                               8.6=c²

riemer m. <3

Michelle's Scribepost for January 6, 2010

Question 6

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

a² + b² = c²
27² + 27² = 37.1²
(27 x 27) + (27 x 27) = 37.1²
729 + 729 = 37.1 ²
1458 = 37.1 ²

37.1 x 37.1 =1376.41

√1458 = 38.18m
√1376.41= 37.1m

It is not a right triangle because the distance between home and second base is 37.1m and isn't 38.2m.

( I wasn't sure how to show my work , so sorry. )

Princess' Scribepost for January 6, 2010

Question No. 4

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

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

The height of the pole is 9.8 metre.

Shania's Scribepost for January 5, 2010

Pg. 104 : Question number 11

The right triangle below has a square attached to its hypotenuse. What is the perimeter of the triangle? Give your answer to the nearest tenth of a centimeter.

√914=30.2

30.2=C²

C²-A²=B²

30.2²-17²=B²

(30x30)-(17x17)=B²

914-289=B²

625=B²

√625=√B²

25=B

A+B+C=permeter

17+25+30.2=perimeter

72.2=perimeter

SORRY THIS IS LATE.

Jeric's Scribepost for January 5, 2010

Question :
What is the length of the red diagonal in the box? Express your answer to the nearest tenth of a millimetre.

Answer :

a2 + b2 = c2
7 squared + 12 squared = c2
( 7 x 7 ) + (12 x 12 ) = c2
49 + 144 = c2
193 = c2
square root of 193 = square root of c2
13.9 mm = c2

a2 + b2 = c2
5 squared + 13.9 squared = c2
( 5 x 5 ) + ( 13.9 x 13.9 ) = c2
25 + 193.2 = c2
218.2 = c2
square root of 218.2 = square root of c2
14.8 mm = c2

The length of the red diagonal box is 14.8 mm .

THNX TO JOMARI FOR HELPING ME ... and the box

sorry if it makes no sense I will try to explain in class.


SORRY FOR NO PICTURE ... COULDN'T GET IT ON MY!!!! COMPUTER.

Jose's scribepost for January 5th, 2010

QUESTION NUMBER 10 FOUND ON PAGE 104 :


What is the minimum distance the player
at third base has to throw the ball to get
the runner out at first base? Express your
answer to the nearest tenth of a meter.



Since 3rd base has to get the ball to 1st base, I figured out the triangle that it makes and it looks like :

After, I figured out the steps to finding the answer :







a² + b² = c²
27² + 27² = c²
( 27 x 27 ) + (27 x 27 ) = c²
729 + 729 = c²
√1458 = c²
38.2 = c²



Then I put it in the missing space : The distance thrown was 38.2 M.