Friday, April 30, 2010

Solving one-step equations

1. Using inspection, mental math

Eg. a + 4 = 12
8 + 4 = 12
12 = 12

Ask yourself what something + 4 = 12 or 12 - something = 4

Try these:

14 = k + 5
14 = 9 + 5

t - 3 = 11
14 - 3 = 11

10 - y = 8
10 - 2 = 8


2. Model (make a picture) and solve

Eg.


Bill rides 4 km to the bridge then rides to work. In total he rides 11 km. How far from the bridge to work?



4 + y = 11

4 + 7 = 11






3. Apply the opposite operation


Eg. c + 22 = 56
- 22 = -22
c = 34

Check- c + 22= 56
34 + 22 = 56
56 = 56



1st step - Isolate the variable (get the letter by itself)

2nd step - Apply the opposite operation

3rd step - Check your answer. Substitute the answer for the letter of the original equation



Opposite operation - An operation that "undoes" another operation
* subtraction and addition are opposites
* division and multiplication are opposites

Solve by applying the opposite operating - Check your answer:


1. n + 7 = 26
- 7 = -7
n = 19

Check - n + 7 = 26
19 +7 = 26
26 = 26

2. d - 3 = -5
+3 = +3
d = -2



Check - d - 3 = -5
(-2) - 3 = -5
-5 = -5








Page 398-401 # 1-22 is HOMEWORK!
http://www.mytextbook.ca/

Thursday, April 29, 2010

Math Playground

Try some of these games, during your long weekend.

http://www.mathplayground.com/

Tuesday, April 27, 2010

Soliving Equations

Solving Equations:

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




2b + 1 is EQUAL to 5

one way is to for you to use a scale.


[ps , i am sorry I can not do a cup so I am going to draw a square instead]

1c + 4 = 5



1c + 4 = 5




Add Image

2c(cups) + 3 = 5



Writing expressions - the expression can be writen using a single constant,a single variable or a combination of operations with constants , variables, or numeral co efficent

2 - numerical co efficient
y - variable
7 - constant

Write the following Equation





c + 3 = 7


expression - 3 5
variable - c
numerical coefficiant - 3
constant is - 5




equation - 4 + 10
variable - c
numerical coefficiant -2
constant -4, and 10.

Show using cups + counters
four times a number minus five equals
write an expression or a eqution
I.D variables, numerical coeficents, constands

Websites :
http://www.studygs.net/equations.htm
http://www.sosmath.com/algebra/solve/solve0/solve0.html (might help with future reference.)

I am sorry but I couldn't find a video because they were too advanced




Thursday, April 15, 2010

Integers

Using a number line to add integers.

A vertical Number line.
Just in case:
Zero pair - A pair of integer chips with one chip representing +1 and 1 chip representing.
Opposite integers - Two integers with the same numeral but different signs.

(+2) + (+3) = 5
(-4) + (-2) = -6
(+3) + (-2) = 1

Positive Numbers move right. Negative numbers move left.
A number line can be vertical also.



Page 319 - 322 is homework! :]



Wednesday, April 14, 2010

April 14 2010 Integers

Zero Pair
-a pair of integer chips with one chip reperesenting +1 and -1.
eg. +1 -1
The pair represent 0 because
(+1) + (-1) = 0
Opposite Integers
-two integers with the same numeral (number) but different signs. (+ -)
eg. + + - -
+2 -2
You can use these symbols to help add positive and negative integers.
eg. + + + + + - - - + - zero
+ - zero
+ - zero
+ +1
+ +1
5 + (-3) =2
Show using chips
(+2) + (+3) (-1) + (-5) (+4) + (-2) (+3) + (-6)
++ +++ = ++2 - - - - - - - - -2 ++++ - - + - 0 +++ - - - - - - + - 0
++2 - -1 + - 0 + - 0
+ 1 - -1 + 1 + - 0
- -1 + 1 - -1
- -1 - -1
- -1
Here's a good video about adding and integers

Here's a link to a good site

http://www.mathsisfun.com/positive-negative-integers.html

Sorry about having no pictures something was wrong with saving it.

Remember!!!

Pg.313 to 315 is homework!!!

Comment and suggest if you see any mistakes. Thanks

Tuesday, April 13, 2010

Integers

Integers-positive and negative whole numbers and zero
*eg. 2, -6, 91, +103, -10000

..not integers. 3/4, +1/2 , 4/5, 0.1. -0.7, 91.3, 95%, -60%

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

Monday, April 5, 2010

Create Circle Graphs

1. Construct(make, build) a circle
Use a string, compass or trace a circle.
2. Create the Central Angles
- central angle- is an angle formed by 2 radii
- the vertex of the angle is at the centre of the circle

















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

















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

Step 1. Find out how many in total.
3+9+18= 30

Step 2. Convert to %
3 = 1 = 10 10% 1-3 days
30 10 100

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

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








%|degrees
100|360
50 | 180
25 | 90
10 | 36


Convert % to degrees.
10% of 360= 36 degrees
use a protractor to measure the central angle

30% of 360= 108 degrees
60% of 360= 216 degrees


Homework
Pages 296-297
Questions 4-13