Thursday, April 29, 2010

Math Playground

Try some of the games here, during your long weekend.

http://www.mathplayground.com/

Solving One Step Equations

1.) Using Inspections; Mental math

a + 4 = 12

Ask yourself what plus 4 equals to 12 or 12 - something to equal 12 .

8 + 4 = 12

12

try:

1.) 14 = k + 5

9 + 5

14

2.) T - 3 = 11

14 - 3 = 11

11

3.) 10 - y = 8

10 - 2 = 8

8

2.) Model and Solve .

model : 11 - 4 = 7

OOOOOOOOOOO - OOOO = OOOOOOO

3.) Apply The Opposite Operation.

C + 22 = 56

- 22 -22

1st. Isolate the variable.

2nd. Apply the opposite operation.

3rd. check the answer,substitute the answer for the letter of the original equation.

Opposite Operation- An operation that "undoes" another operation.

Eg.

division and multiplication.

N + 7 = 26 d - 3 = - 5

-7 -7 +3 +3

19 + 7 = 26 (-2) - 3 = -5

C = Cup.

C + 3 = 6

Don't forget to do your homework!

Tuesday, April 27, 2010

Solving Equations

Equation-a mathematic statement with two expressions that have the same value.

Eg. X + 2 =3

X = Expression
2 = Equation
3 = Expression

2B + 1 = 5

c = Cup.

c + OOOO = c + 4

2c + 3 =

2 = Numerical Coefficient
c = Variable
3 = Constant

Writing Expressions-An expression can be written using a single constant,variable,or a combination of operations with constants,variables,or numerical coefficients.

2y-7
2 = numerical coefficient
y = variable
- = operation
7 = constant

Write The Equation
c + 3 = 7
4 + 3 = 7
c + OOO = OOOOOOO
OOOO + OOO = OOOOOOO

c + c + OOOO = OOOOOOOOOO
constants = 4 and 10

Home Work!!
show using cups and counters 4 times a number minus five equals seven.
Write as a Expression
I.D variables,coefficients and constants.

Friday, April 16, 2010

Subtracting Integers

Substracting Intergers using Chips: positive chip and negative chip.

(-5) - (-3) =

2 - 5 =

When subtracting something that isn't there we used a
zero pair.
(-1) - (-3) =

Show using chips.

This morning it was -2. This afternoon will be 3. Determine the difference of these temperatures.

FOR HOMEWORK:
pg. 327 - 329
1 - 21 (odd)

Thursday, April 15, 2010

Using a Numberline to add Intergers

a) (+2)+(+3)= +5

b) (-4)+(-2)= (-6)

c) (+3)+(-2)= 1

d)(-5)+(+4)= (-1)

Positive numbers move right
Negative numbers move left

A Numberline can go Vertical ( up and down)

Monday, April 12, 2010

Areas and Integers

Areas:
I am creating two circular flower beds in my front yard. The first flower bed has a diameter of 12m and the second one has a radius of 8m. My front yard is 20m wide and 30m long. The rest of the front yard is grass will I have to cut?

r=d/2
r=12/2
r=6

Area of a circle:
A=pi r squared
A=3.14 multiplied by 6m squared
A=3.14 multiplied by 36
A=113.04m squared

Area of a circle:
A=pi r squared
A=3.14 multiplied by 8m squared
A=3.14 multiplied by 64
A=200.96m squared

Area of a rectangle:
A=b multiplied by height
A=30 multiplied by 20
A=600m squared

113.04m squared + A=200.96m squared= 314m squared

600m squared - 314m squared= 286m squared

You would have to cut 286m squared of grass.

You have a triangular shaped yard with a base of 10m and a height of 15m. You are creating a sand box for your kids. The sandbox has a circumference of 6.28m. How much yard do you have left.

C=pi d
C=2 pi r
6.28=2 (3.14) r
6.28/6.28= 6.28r/6.28
1=1r
1m=r

Area of a circle:
A=pi r squared
A=3.14 multiplied by 1m squared
A=3.14 multiplied by 1
A=3.14m squared

Area of a triangle:
A=b multiplied by height/2
A=10 multiplied 15/2
A=150/2
A=75m squared

75m squared - 3.14m squared= 71.86m squared

You would have 71.86m squared of yard left.

Integers:

Integers are positive and negative whole numbers and zero.

eg.2, -6, 91, +103, -1000, 0.
not integers: -3/4, +1/2, 4/5, 0.1, -0.7, 91.3, 1.3, 95%, -60%.

Integers can be shown on a number line or using integer chips.

BLUE CHIPS= negative numbers RED CHIPS= positive numbers

000 = -3

000= +3

Homework:

Identify each integer

a) 0 b) 0 c)000 d)00000 e)0000000 f)00000

Represent each integer:

+2, 8, -4, +7, -6, -8.

Here is a link for a video. I went on YouTube to find a video and there was no place that even shows the embed so I had to post the link. Sorry for the inconvenience. http://www.youtube.com/watch?v=SZf2UUsMhfI&feature=PlayList&p=3A35B91F32C28418&playnext_from=PL&playnext=1&index=47

Monday, April 5, 2010

Create Circle Graphs

Construct a Circle
-compass, string

Create Central Angle
-central angle is formed by 2 radii, the vertex of the angle is at the center

Example

They got 360 in a circle because there is 365 days in a years but 365 is to hard to work.

25% like strawberry
25% like vanilla
50% like chocolate

Make a circle graph for the following info. 3 kids use the computer 1-3 days a week. 9 kids use the computer 0 days a week. 18 kinds use computer 4 or more days a week

Step 1 find how many total

3 + 9 + 18 = 30

Step 2 convert to percent

3/30 = 1/10 = 10/100 10% 1-3 days

9/30 = 3/10 = 30/100 30% 0 days

18/30 = 6/10 = 60/100 60% 4 or more

Step 3 convert % to degrees

10% of 306* = 36*

30% of 360* = 108*

60% of 360 +216*