A circle is a graph that represented data using sections of a circle.
sector  section of a circle formed by 2 radii and the area of a circle connecting the 2 radii.
eg.
Pets of students in Mr. W's class (24students)
1. What is the tittle?
2. What are the different categories represented by graph?
3. What percent of the class has a dog? and how many students have a dog?
4. % of class with cat? how many students have a cat?
5. What % of the circle is represented by all the sectors?
6. Would this graph make sense if the title or a sector labels were missing?
Video:
http://www.youtube.com/watch?v=jFge51Rhv4
Link:
http://socrates.bmcc.cuny.edu/cpe/circle_pie.html
Hope this helps!
thanks.
Wednesday, March 24, 2010
Tuesday, March 23, 2010
Lance's Scribe
Find the diameter of a circle with a radius of 12.6m.
Show the formula you used and all the work.
d=2r
d=2(12.6)
d=25.2m.♫♫♫
Find the radius of a circle when the diameter is 10.5cm.
Show formula and work.
r=d/2
r=10.5/5
r=5.25cm.♠
Find the circumference of a circle with a diameter of 3mm.
Show formula and work.
c=pi d
c=(3.14)(3mm)
c=9.42 mm.♦
Find the circumference of a circle with a radius of s.m.
Show formula and work
c=2pi r
c=2(3.14)(5)
c=10 314
c=c=31.4m.♥
Find the diameter of a circle with a circumference of 12.56 cm.
Show formula and work
d=c/35
d=1256/3.14cm
d=4cm.☻
Find radius of follow circles
d=4cm
d=10cm
c=15.7m
c=3.14cm. ☺
Lance's Blog
Show the formula you used and all the work.
d=2r
d=2(12.6)
d=25.2m.♫♫♫
Find the radius of a circle when the diameter is 10.5cm.
Show formula and work.
r=d/2
r=10.5/5
r=5.25cm.♠
Find the circumference of a circle with a diameter of 3mm.
Show formula and work.
c=pi d
c=(3.14)(3mm)
c=9.42 mm.♦
Find the circumference of a circle with a radius of s.m.
Show formula and work
c=2pi r
c=2(3.14)(5)
c=10 314
c=c=31.4m.♥
Find the diameter of a circle with a circumference of 12.56 cm.
Show formula and work
d=c/35
d=1256/3.14cm
d=4cm.☻
Find radius of follow circles
d=4cm
d=10cm
c=15.7m
c=3.14cm. ☺
Lance's Blog
Monday, March 22, 2010
Area
Area
the space a shape takes up
described in square units eg. 4cm²
the space a shape takes up
described in square units eg. 4cm²
Area of square or rectangle
=6x2
=12cm²
Parallelogram
Base x Height
eg. the base 10cm and the heght is 5 cm
A=bxh
A=10x5
A=10x5
A= 50 cm²
Finding the Area of a circle
Use pieces of circle to create a shape very close to a parallelogram.
Close to parallelogram
H=Radius
B=½ circumference
Ap=bxh
Ao=2 pi r ÷2 x r
Ao=pi xrxr
The simple formula is Ao=pi r²
The simple formula is Ao=pi r²
*Sorry the pi symbol doesn't work.
Find the Area of a circle with the radius of 10m.Show formula and work.
Ao=pi r²
Ao=3.14xrxr
Ao=3.14x100
=314m²
Find the Area of the following circles
the first circle has the radius of 8cm
the 2nd circle has the radius of 14.8m
Ao=pi r²
Ao=3.14x8x8
Ao=3.14x64
=200.96cm²
Ao=3.14x8x8
Ao=3.14x64
=200.96cm²
Ao= pi r²
=3.14x14.8x14.8
=3.14x219.04
=3.14x219.04
=687.79m²
To find the Area of a circle,and the question gives you the diameter.
You should divide it into 2.After you find the quotient use formula to answer the question.
Wednesday, March 17, 2010
Circles
Circles
radius  distance from the centre of the circle to the outside edge. represented by small b
diameter  distance across a circle through its centre . represented by small d
a diameter is 2 radii d=2r r=d/
construct a circle a radius of 4cm
1. start with centre of circle
2. measure the length of radius on a string
3. pencil at one of string and pin the sting in the centre of the circle.
4. trace an ARC around the centre
using a compass
1. measure a line the length of a radius
2. sharp line of compass in the centre of circle
3. pencil at the other end of the line
4. draw an ARC around the centre
TEXTBOOK:
page 270  272
# 1 15 odd then even
PS:
feel free to comment and tell me ifIi did any mistakes or miss some parts.
thanks.
diameter  distance across a circle through its centre . represented by small d
a diameter is 2 radii d=2r r=d/
construct a circle a radius of 4cm
1. start with centre of circle
2. measure the length of radius on a string
3. pencil at one of string and pin the sting in the centre of the circle.
4. trace an ARC around the centre
using a compass
1. measure a line the length of a radius
2. sharp line of compass in the centre of circle
3. pencil at the other end of the line
4. draw an ARC around the centre
TEXTBOOK:
page 270  272
# 1 15 odd then even
PS:
feel free to comment and tell me ifIi did any mistakes or miss some parts.
thanks.
Wednesday, March 10, 2010
Adding Mixed Numbers
1 5/6 + 1 5/6 =
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 = 3 2/3
steps:
1. add the whole numbers
2. find common denominator for fractions
3. add the fractions
4. add the whole numbers to the fractions
eg.
1 1/3 + 2 1/3 = 3 2/3
3 1/6 + 2 5/6 = 5 6/6 = 6
3 2/3 + 2/3 = 3/43 = 4 1/3
eg.
1 1/2 + 2 1/3 = 3 2/6 = 3 1/3
2 1/2 + 4 1/6 = 6 4/6 = 6 2/3
homework:
page 249
# 1  3
PS:
If I did any mistakes or miss some parts, feel free to comment and tell!
thanks.
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 = 3 2/3
steps:
1. add the whole numbers
2. find common denominator for fractions
3. add the fractions
4. add the whole numbers to the fractions
eg.
1 1/3 + 2 1/3 = 3 2/3
3 1/6 + 2 5/6 = 5 6/6 = 6
3 2/3 + 2/3 = 3/43 = 4 1/3
eg.
1 1/2 + 2 1/3 = 3 2/6 = 3 1/3
2 1/2 + 4 1/6 = 6 4/6 = 6 2/3
homework:
page 249
# 1  3
PS:
If I did any mistakes or miss some parts, feel free to comment and tell!
thanks.
Subtracting Mixed Numbers
If you have like denominators, like
1 2/4 in lowest terms is 1 1/22 3/4  1 1/4,
then use fraction strips.
eg.
Second Method
Subtract the whole numbers,
2 3/41 1/4 21=1
then subtract the fractions
3/41/4=2/4
1 2/4 in lowest terms is 1 1/2
a) 2 2/31 1/3=1 1/3 b)3 7/81 3/8=2 4/8= 2 1/2 c)4 3/41/4= 4 2/4= 4 1/2
Subtracting Mixed Numbers With UNLIKE Denominators
3 3/8 1 1/2 3=24/8 1=8/8
3 3/8 1 1/2 3=24/8 1=8/8
27/812/8=15/8=1 7/8
Another Way to Regroup
3 3/81 1/4
2 11/81 4/8 (borrowed 8/8 or 1 from 3)
=1 7/8
a)4 1/43 2/5 b)4 1/47/8
4 5/203 8/20 4 2/87/8
3 25/203 8/20 3 10/87/8
=17/20 =3 3/8
This concludes my blog about subtracting mixed numbers but remember...
Pi day is on Tuesday March 16 at lunch time.
Clues will be all over the school and the first person to find all of them and get to the final destination will win a prize.
Good luck, and Good Bye!
Labels:
2010,
Alec M.,
fractions,
March 10,
mixed numbers,
subtracting
Wednesday, March 3, 2010
Subtracting Fractions with Unlike Denominators
* You must find a common denominator or LCD & use equivalent fractions.
eg. 3/4  1/2 = 1/4
solution :
3/4 = 3/4

1/2 = 2/4
___
1/4
2/3  1/4 = 5/12
solution :
2/3 = 8/12

1/4 = 3/12
____
5/12
3/4  2/4 = 1/4
solution :
3/4

2/4
____
1/4
8/12  3/12 = 5/12
solution :
8/12

3/12
_____
5/12
3/4  1/8 = 5/8
solution :
3/4 = 6/8

1/8 = 1/8
_____
5/8
* Unit Fractions : a fraction with a numerator of 1.
eg. 1/2, 1/3, 1/10, 1/100, 1/anything.
eg. 3/4  1/2 = 1/4
solution :
3/4 = 3/4

1/2 = 2/4
___
1/4
2/3  1/4 = 5/12
solution :
2/3 = 8/12

1/4 = 3/12
____
5/12
3/4  2/4 = 1/4
solution :
3/4

2/4
____
1/4
8/12  3/12 = 5/12
solution :
8/12

3/12
_____
5/12
3/4  1/8 = 5/8
solution :
3/4 = 6/8

1/8 = 1/8
_____
5/8
* Unit Fractions : a fraction with a numerator of 1.
eg. 1/2, 1/3, 1/10, 1/100, 1/anything.
http://www.wisconline.com/objects/ViewObject.aspx?ID=abm6007
Tuesday, March 2, 2010
Adding fractions with unlike denominators.
Adding fractions with unlike denominators.
Eg. 1/2 + 1/3 = 1 apple + 1 orange = 2 fruits
We must find a common denominator.  A multiple of the denominators of a set of fractions.
 Eg. a common denominator for 1/4 and 1/6 is 12 because common multiple of 4 and 6 is 12. 4  4, 8, (12), 16 6  6, (12), 18, 24
Eg. 1/2 + 1/3 = 3/6 + 2/6 = 5/6
Homework: Math Links textbook pages 234236 # 421 odd numbers. :)
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