Circle Graph March 24, 2010

Circle Graph
A circle graph is a graph that represents data using sections of a circle

Sector - A section of a circle formed by 2 radii and the arc of a circle connecting the 2 radii

Eg. Circle graph

Favourite NFL teams


General

More specific


How many were asked ? 500




Pets of students in Mr. W's Class (24 Students)


Questions

1)What is the Title? Pets of students in Mr. W's Class? Pets of students in Mr. W's Class (24 Students)
2)What are the different categories represented by the graph ? Cat,Dog,Other and No pet
3)What is the percent of the class has a dog?25%
How many students have a dog? 6
4)% of class with cat? 33%
How many students have a cat ? 8
5) What % of the circle is represented by all sectors? 100%
6)no.






Pages 290 - 291










*ps sorry , the pages didn't come up very well. ):
and if i need to improve something please tell me



Link

http://cstl.syr.edu/fipse/TabBar/ReadCirc/REVCIRCL.HTM

Video

Area

Area is the space a shape takes up. It is described in square units. (4 cm 2)

Review:

Area of a square or rectangle:

Length times width.
A=L x W
A=6 x 2
A=12 cm 2

Area of a parallelogram

Base times height

A= B x H
A= 10 x 5
A= 50 m 2




Area of a circle

A= pi r 2



Use pieces of circle to create a shape close to a parallelogram.

Area problems

find the area of a circle with the radius of 10 m.

A= Pi r 2.
A=3.14 x 10 2
A=3.14 x 100
A=314 m 2.

Find area of following circles:


8 cm
A= pi r 2
A= 3.14 x 82
A= 3.14 x 64
A= 200.96 cm2

14.8 m
A= pi r 2
A= 3.14 x 14.82
A= 3.14 x 219.04
A= 687.79 m2


Divide the diameter by 2 to get the radius. 20 cm / 2 is 10 cm.
A= pi r 2
A= 3.14 x 102
A= 3.14 x 100
A= 314 cm 2

6.8 m / 2 is 3.4
A= pi r 2
A= 3.14 x 3.42
A= 3.14 x 11.56
A= 36.30 m 2

Here is a link of a video to help you!

Finding a diameter, circumference, radius of a circle.

The picture above is the radius and the diameter of a circle.

This is what we worked on in Math on March 19. 2010.

Find the diameter of a circle with a radius of 12.6 m.

Show the formula you need and all the work.
Answer:

• d = 2r
• d = 2 ( 12.6 )
• d = 25. 2 m

Find the radius of a circle when the diameter is 10.5 cm.
Show the formula and work. Remember, when finding
the radius of a circle, make sure you divide it by two.

• r = d / 2
• r = 10.5 / 2
• r = 5.25 cm

Find the circumference of a circle with a diameter of 3 mm.
Show formula and work.

• c = π d
• c = 3.14 ( 3 )
• c = 9.42 mm

Find the circumference of a circle with a radius of 5m.
Show formula and work.

• c = 2 π r
• c = 2 (314 ) ( 5 )
• c = 10 ( 3.14 )
• c = 31.4 m

When finding a circumference, you have to divide it by π.

When finding a diameter, you have to multiply the number by 2.

And when finding the radius, you divide it by two. Hope this helps. (:

Please alert me if I get an answer wrong. Thanks. :)

Circles

Parts of a circle
-centre
-radius
-diameter
-circumference-is the distance around a circle
-usually represented by c

-this is a linear measurement

-pi-is the ratio of the circumference of a circle to its diameter

Pi is usually 3.14

Heres a link to help you:

http://www.youtube.com/watch?v=1XFkAZW-rWg

Adding Mixed Numbers

Here is what we learned on Monday

Cheese 6/6=1 5/6 Bacon 6/6 5/6 1 5/6+ 1 5/6=
Here is one way to add this
1+1+5/6+5/6=
2+5/6+5/6=
2+10/6=
2+6/6+ 4/6=
2+1+4/6=
3 4/6
Lowest Terms: 2/3

Another strategy you can use is to create a diagram.

Take one from the last one to make the second one whole. That gives us 3 wholes and 4/6. In Lowest terms we got 3 2/3.

Steps for adding mixed numbers
1.Add the whole numbers
2.Find a common denominator for the fraction
3.Add the fractions
4.Add the whole numbers to the fractions

The word "And" in math means decimal or addition eg. 1.5 or 1+1/2

Here's 2 links you can follow to watch a video to understand more about mixed numbers. http://www.youtube.com/watch?v=ed6p1huCZG0http://www.youtube.com/watch?v=eN4gqykQ6L8&NR=1&feature=fvwp

Sorry about posting this so late, I had a bit of trouble with posting this.

I hope you enjoyed my blog post, tell me if I made any mistakes or if I could improve on anything:)

Unlike Denominator

3 3/8 - 1 1/2=???
Steps to find the answer:
1.Find the common denominator
2.Regroup
3.Then change into a mixed fraction.










Another way:





http://www.youtube.com/watch?v=2Pr5OEHx3lI

subtracting fractions with unlike denominators. you must find a common denominator and use a equivalent fraction.