What are intersecting lines?

Two or more lines that meet at a point are called intersecting lines. That point would be on each of these lines. There like a four way road.

    e.g

                  

What's a radius?

Radius is the part of a circle that starts from the center to the side of the circle.

The formula for radius is d/2.

e.g

the diameter is 66cm, what is the radius?

r=d/2

r=66/2

r=33cm.

What is a circumference?

Circumference is the distance of the outside of the circle. It's basically the perimeter of the circle.













-the outside circle indicates the circumference



The formula for circumference is 2pr(2 x p x r).

 e.g.

    The radius is 3m, what is the circumference?


    A=2pr
    A=2 x 3.14 x 3
    A=6.28 x 3
    A=18.84m
     

 

Formula for Area

Area is the amount of surface the circle covers. It is measured in squared units.







The formula for area is pr2(pi x r squared).




e.g.

    the radius is 2m, what is the circumference?
       
    A=pr2
    A=3.14 (2)2
    A=3.14 x 2 x 2
    A=6.28 x 2
    A=12.56 m2




   You always need to put the units you are working with.
    Explaining it like this will give an accurate answer.

What is a diameter?

Diameter is part of a circle. It is a measurement across from a one point on a side of a circle going through the center point the onto the other side. The formula for diameter is 2r=d. 2 radii is equal to 1 diameter.

Mixed Numbers

Denominator and Numerator

How to Simplify Fractions

Equivalent Fractions

Improper Fractions

Question no.10 from textbook

You need to answer these problems by adding the fractions and simplify if needed.

These are the problems:

Math book page 146 number 4.

4. Show how to find each amount.

a) 10% of 25 b) 25% of 84

c) 50% of 98 d) 75% of 124

Bar notation, percents and decimals

Change each fraction to a repeating

decimal. Then use bar notation to show

the repeating part

What I did is I answered every problem,

next is putting bar notation, bar notation

makes stuff easier because it means repeatition of

a number. For example if you put a bar of 6 its

automatically 66666666666 in Math.

School lesson Converting fractions, decimals and percents.

This was the lesson Mr.Isfeld taught last Wednesday Nov.9, 2011.

It was about converting fractions, decimals and percents.

Fractions to decimals

Example 1: Express 3/4 as a Decimal

Step 1: We can multiply 4 by 25 to become 100

Step 2: Multiply top and bottom by 25:

×25
3	=	75
4		100
×25

Step 3: Write down 75 with the decimal point 2 spaces from the right (because 100 has 2 zeros);

Answer = 0.75

Example 2: Express 3/16 as a Decimal

Step 1: We have to multiply 16 by 625 to become 10,000

Step 2: Multiply top and bottom by 625:

×625
3	=	1,875
16		10,000
×625

Step 3: Write down 1875 with the decimal point 4 spaces from the right (because 10,000 has 4 zeros);

Answer = 0.1875

Example 3: Express 1/3 as a Decimal

Step 1: There is no way to multiply 3 to become 10 or 100 or any "1 followed by 0s", but we can calculate an approximate decimal by choosing to multiply by, say, 333

Step 2: Multiply top and bottom by 333:

×333
1	=	333
3		999
×333

Step 3: Now, 999 is nearly 1,000, so let us write down 333 with the decimal point 3 spaces from the right (because 1,000 has 3 zeros):

Answer = 0.333 (accurate to only 3 decimal places !!)

Example: Express 0.75 as a fraction

Step 1: Write down 0.75 divided by 1:

0.75

1

Step 2: Multiply both top and bottom by 100 (there were 2 digits after the decimal point so that is 10×10=100):

× 100
0.75	=	75
1		100
× 100

(Do you see how it turns the top number
into a whole number?)

Step 3: Simplify the fraction (this took me two steps):

	÷5		÷ 5
75	=	15	=	3
100		20		4
	÷5		÷ 5

Answer = ³/₄

Note: 75/100 is called a decimal fraction and 3/4 is called a common fraction !

Decimals to Fractions

Example: Express 0.625 as a fraction

Step 1: write down:

0.625

1

Step 2: multiply both top and bottom by 1,000 (there were 3 digits after the decimal point so that is 10×10×10=1,000)

625

1,000

Step 3: Simplify the fraction (it took me two steps here):

	÷ 25		÷ 5
625	=	25	=	5
1,000		40		8
	÷ 25		÷ 5

Answer = ⁵/₈

Percent to Decimals

this link will help decimals.html">http://www.mathsisfun.com/converting-fractions-decimals.html

Order of Opeartions

Before you I answer this

I will have to follow

the following steps called

"BEDMAS" as shown below.

And don't forget to do the operations 4x3+12÷2=

left to right. 12+12÷2=

Brackets 12+6

Exponent 18

Division

Multiplication

Addition

Subtraction

LINK:http://mathcentral.uregina.ca/QQ/database/QQ.09.07