A circle graph is a graph that is represents data using sections of a circle.

Sector- A sector of a circle formed by 2 radii and the arc of the circle connection the 2 radii.

Example of a General Graph and a more Specific Graph

How many were asked ?

1) Title = Pets of students in Mr.W's class (24 students)

2) What are the different categories represented by the graph ?

- Cat, Dog, Other, No pets .

3) What percent of the class has a dog ? How many have a dog ?

- 25 % of the class has a dog .

- 6 kids have a dog

4) What percent of the class has a cat ? How many have a cat ?

- 33 % of the class has a cat .

- 1/3 of 24 = 8 Kids have a cat .

5) What percent of the circle is represented by all the sectors ?

- 100 %

6) Would this graph make sense if the title or sector labels were missing ?

- No, because then we wouldn't understand what the graph is all about .

Create your own Circle Graph on : http://www.mathplayground.com/piechart.html

Watch a video about circle graphs : http://www.youtube.com/watch?v=jFg-e51Rhv4

## Wednesday, March 24, 2010

## Monday, March 22, 2010

## Wednesday, March 17, 2010

### Circle

Parts of the Circle

- centre
- radius
- diameter
- circumference - is the distance around a circle

-this is a linear measurement

π = pi- the ratio of the circumference of a circle to its diameter

1. Find circumference if diameter is 2m.

2. Find circumference of each circle.

## Tuesday, March 16, 2010

### Circles

Radius - a distance from the centre of the circle to the outside edge.

- represented by r

Diameter - distance across a circle through its centre

- represented by d

*A diameter is 2 radii.*

**Construct a circle with a radius of 4cm.**

1. Start with centre of a circle.

2. Measure the length of a radius on a string.

3. Pencil at one end of string and pin the string 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 point of compass in the centre of the circle.

3. Pencil at the other end of the line.

4. Draw an arc around the centre.

pages 270-272

# 1-15

Do literacy link also.

**Video/s and Link/s**## Friday, March 12, 2010

### Today at school :)

Homework : 260- 261 (Chapter Review)

And 262- 263 ( Practice Test )

Remember : NO SCHOOL ON MONDAY :)

And 262- 263 ( Practice Test )

Remember : NO SCHOOL ON MONDAY :)

## Wednesday, March 10, 2010

### Subtracting with mixed numbers

If you have unlike denominators :

2 3/4 - 1 1/4

One method use fraction strips

* Second method = Subtract whole numbers

Answer the following :

a) 2 2/3 - 1 1/3 =

2 - 1 = 1

2/3 - 1/3 = 1/3

1 1/3

b) 3 7/8 - 1 3/8 =

3 - 1 = 2

7/8 - 3/8 = 4/8

2 4/8

Lowest terms = 2 2/4, 2 1/2

c) 4 3/4 - 1/4 =

3/4 - 1/4= 2/4

4 2/4

Lowest terms - 4 1/2

Unlike Denominators

- Find the common denominator

We don't want to have a whole number (2) and a negative fraction so we must regroup

* ANOTHER WAY TO REGROUP

Steps :

1. Subtract the whole numbers

2. Subtract fractions

3. Combine them

Answer the following ; a ) 4 1/4 - 3 2/5

b) 4 1/4 - 7/8

2 3/4 - 1 1/4

One method use fraction strips

* Second method = Subtract whole numbers

Answer the following :

a) 2 2/3 - 1 1/3 =

2 - 1 = 1

2/3 - 1/3 = 1/3

1 1/3

b) 3 7/8 - 1 3/8 =

3 - 1 = 2

7/8 - 3/8 = 4/8

2 4/8

Lowest terms = 2 2/4, 2 1/2

c) 4 3/4 - 1/4 =

3/4 - 1/4= 2/4

4 2/4

Lowest terms - 4 1/2

Unlike Denominators

- Find the common denominator

We don't want to have a whole number (2) and a negative fraction so we must regroup

* ANOTHER WAY TO REGROUP

Steps :

1. Subtract the whole numbers

2. Subtract fractions

3. Combine them

Answer the following ; a ) 4 1/4 - 3 2/5

b) 4 1/4 - 7/8

## Wednesday, March 3, 2010

### Subtracting Fractions With Unlike Denominators

**To subtract fractions with unlike denominators, you MUST find a**

**common denominator and use equivalent fractions.**

**eg. 3/4 - 1/2**

**eg.**

**2/3 - 1/4**

**eg. 3/4 - 1/8**

**Unit Fraction-**A fraction with a numerator of 1.

Do page 241- 244 # 1-23 odd THEN even.

- Do the odd numbers for homework.

## Tuesday, March 2, 2010

### Adding Fractions With Unlike Denominator

Subscribe to:
Posts (Atom)