Категории: Все - bases - division - algorithms - rules

по Roxanne Cavalera 7 лет назад

423

MTE 280 - Roxanne Cavalera

The text explores mathematical concepts related to different numerical bases, focusing on how numbers are converted from base ten to other bases, and vice versa. Examples illustrate conversions, such as transforming 15 into base five (

MTE 280 - Roxanne Cavalera

Week 1-14

Fractions

Definition:


When a whole is divided into equal pieces, if fewer equal pieces are needed to make up the whole, then each piece must be larger. When two positive fractions have the same numerator, they represent the same number of parts, but in the fraction with the smaller denominator, the parts are larger.

Rule:

K, C, F or K, C, I = Keep, Change, Flip (Inverse)


*Follow same produce as Multiplication of Fractions with unlike denominators

Multiply

Simplify first = top to bottom, and across


Multiply straight across then change to a Mixed number

Subtraction

You have to change the denominators to be the same number by finding out what is missing in each fraction (denominator).


Simplify = to to bottom


Then you subtract straight across.


Change to a mixed number


Addition

Example:


2 + 5 = 2 x 6 + 5 x 2 = 12 + 10 = 22 (divide by 2) = 11

3 + 9 = 3 x 6 + 9 x 2 = 18 + 18 = 18 (divide by 2) = 9


Answer is:


11 or simplify 11 = 1 2/9

9 or simplify 9

Unlike Denominators

You have to change the denominators to be the same number by finding out what is missing in each fraction (denominator).


Simplify = to to bottom


Then you add straight across.


Change to a mixed number

Simplify

Example:


12 (divided by 4) = 3

20 (divided by 4) = 5


OR


12 = 2 x 2 x 3 = 3

20 = 2 x 2 x 5 = 5


OR


y 2 = y x y x 1 = 1

y 3 = y x y x y = y


Equivilency

Example (Set Model):


2 = 4

3 = 6


OR


2 = 6

3 = 9


OR


2 = * * *

3


OR


2 = * * *

3


OR


2 = + + +

3


OR


2 = + + +

3

Greater Than or Less Than

Notes:



Example:


4 is greater than 4

7 is greater than 11


5 is greater than 3

12 is greater than 12


4 ? 10

5 ? 11


4 x11 is less than 10 x11 = 44 is less than 55

5 x11 is less than 11 x11 = 55 is less than 55


OR


4 = 44 is less than 10 = 50

5 = 50 is less than 11 = 44



Linear Model

Example:


5 is greater then 12

9 is greater then 25


l---------l----------l----------l----------l

0----- 12/25------ 1/2------- 5/9-------- 1

Area Model

Example:


4 is less then 10

5 is less then 11



l l l l l l is less then l l l l l l l l l l l l

l l l l l l is less then l l l l l l l l l l l l

l l l l l l is less then l l l l l l l l l l l l








Scientific Notation


Example:


134000 = 1.34 x 105


0.00000761 = 7.61 x 10-6



Properties

Distributive for Multiplication

A = l x w


Examples:


25(15) = 375


10 + 15

20 l 200 l 100 l

+

5 l 50 l 25 l

300 + 75 = 375


4(-3 + 5) + 8


-3 + 5

4 l -12 l 20 l



4(x + 5) = 4x + 20


x + 5

4 l 4x l 20 l


3(x + 7) = 3x + 21


x + 7

3 l 3x l 21 l



10(2x2 - 4x) = 20x2 - 40x


2x2 - 4x

10 l 20x2 l -40x l



4(x2 + 3x -1) = 4x2 + 12x - 4


x2 + 3x - 1

4 l 4x2 l 12x l -4 l



(x + 2)(x + 3) = x2 + 5x + 6


x + 3

x l x2 l 3x l

+

2 l 2x l 6 l



(x + 2)(x + 5) = x2 + 7x + 10


x + 5

x l x2 l 5x l

+

2 l 2x l 10 l

Difference of Squares

Example:


(x + 2)(x - 2) = x2 - 4


x - 2

x l x2 l - 2x l

+

2 l 2x l - 4 l

x2 + ox - 4 = x2 - 4



(3x - 7)(3x + 7) = 9x2 - 49


3x - 7

3x l 9x2 l - 21x l

+

7 l 21x l - 49 l

9x2 + ox - 49 = 9x2 - 49

Factoring

Example:


6x + 15 = 3(2x + 5)


3 l 6x l +15 l

2x + 5



x2 - 3x = x(x - 3)


x l x2 l - 3x l

x - 3


3x2y - 9xy + 6y = 3y(x2 - 3x + 2)


3y l 3x2 y l -9xy l + 6y l

x2 - 3x + 2


Communitive For Addition


Example:


5 + 7 + 2 or 5 + 2 + 7

Associative for Addition


Example:


(4 + 2 + 5) or (4 + 2) + 5 or 4 + (2 + 5)



-5 + (5 + 3) or (-5 + 5) + 3


JUST SOLVE

Rules




Negative Coefficent

Example:


-3(2) = -6


++ ++ ++ ++++

------ ----


-3(-2) = 6


++++++ ++++

-- -- -- ----


-1(-3) = 3


+++ +++++++

--- -------


-2(4) = -8


++++ ++++ ++++

-------- ----


Positive Coefficent

Example:


6(2) = 12


l l l l l l l l l l l l = 12


6(1) = 6


l l l l l l = 6


3(-2) = -6


(- -)(- -)(- -) = -6


5(-4) = -20


(- - - -)(- - - -)(- - - -)(- - - -)(- - - -) = -20



Numberlines

Number Lines: a line with numbers placed in their correct positions




Absolute Value

Absolute Value: how far away a number is from zero


Example:


6 is 6 units from zero

Absolute value of 6 = 6


-6 is 6 units from zero

Absolute value of -6 = 6 or l-6l

Diagram

Draw Diagram: use when you have any numbers bigger than ten.



Examples:


-15 + 436 = +421


- sub. ++

-15 + 436

- 15

+421


Examples:


-47 + (26) = -73


-- add. -

-47 + (-26) 26

+ 47

-73



Tiles

Draw Tiles: use when you have any numbers less than ten.


Examples: Addition:


2 add 4 = -2

+ +

----


-5 add -2 = -7

----- --


Examples: Subtraction:


4 take away 3 = 1

+ + + +


-5 take away -2 = -3

+ + + + +


-5 take away 1 = -4

+ + + + +


Division

6 divided by 6 = 1

6 = Total Number

6 = Number of Groups

1 = Number of Units Inside 1 Group


*If divisor gets smaller = answer gets bigger (Inverse Relationship)

Divisibility Rules
Upwards

382 divided by 3 = 127 1/3



-3 -6 -21 = 1

3 8 2 = 127 1/3

3

Repeated Subtraction

382 divided by 3 = 127 1/3

127 1/3

3 l 382

-30

352

-30

322

-300

22

-15

7

-6

1

Traditional

382 divided by 3 = 127 r1

127 r1

3 l 382

-3

08

-6

22

-21

10

-9

10

-9

Multiplication

6(6) = 36

6 = Number of Groups

(6) = Number of Units Inside 1 Group

36 = Total Number of Whole Groups


*ORDER MATTERS*

Lattice
Expanded
Area Model for Multiplication

1.) A Rectangle with a length of 10 + 1 and a width of 4 - A = 44

Distributive Property:
(4)(10 + 1)
40 + 4 =44

2.) A Rectangle with a length of 10 + 3 and a width of 10 + 2 - A = 156

10 + 3 = 13
10 + 2 = 12
A = 12 x 13 = 156


Alternative Algorithims: Subtraction

Traditonal

47 - 12 = 35

47
- 12
35

Equal Add Ons

47 - 12 = 35

47 + 8 = 55
- 12 + 8 = - (20)
35

Alternative Algorithims:Additon Estimating

31 + 24 + 15 + 42 + 39

80
40
+ 30
150

Front End

31 + 24 + 15 + 42 + 39

30
20
10
40
+ 30
130

Alternative Algorithims: Addition

Compatible Numbers

31 + 24 + 15 + 42 + 39 = 151

2
31 1 + 9 = 10
24 4 + 5 + 2 = 11
15
42 3 + 2 + 1 + 4 = 10
+ 39 3 + 2 = 5
151

Scratch Method

31 + 24 + 15 + 42 + 39 = 151

1 2
31
24
15
2 42
+ 39 1
151

5.) Tradtional

46 + 28 = 74

1
46
+ 28
74

4.) Lattice
3.) Left to Right

46 + 28 = 74

46
+ 28
74

2.) Partial Sum

46 + 28 = 74

46 + 20 = 66
66 + 8 = 74

1.) Expanded

46 + 28 = 74

40 + 6
+ 20 + 8
60 + 14
60
+ 10 + 4
70 + 4 =74

Other Bases

Never have any number bigger than the base number

Other bases to base ten

1.) Convert 23 four to ten = 11
23 four
2 long 3 unit
2(4) 3
8 + 3 = 11

2.) Convert 42 eight to ten = 34
42 eight
4 long 2 unit
4(8) 2
32 + 2 = 34

3.) Covert 123 five to ten = 38
123 five
1 flat 2 long 3 unit
25 + 10 + 3 = 38

Base ten to other bases

Examples:
1.) 15 to base five = 3 long, 0 units = 30 five
2.) 15 to base three = 1 flat, 2 longs, 0 units = 120 three
3.) 17 to base six = 2 long, 5 units = 25 six
4.) 11 to base four = 2 long, 3 units = 23 four
5.) 14 to base three = 1 flat, 1 long, 2 units = 112 three
6.)356 to base four = 11210 four
4 l356
4 l89 r 0
4 l22 r 1
4 l5 r 2
1
7.) 14 to base five = 24 five
5 l14
2 r 4
8.) 14 ro base three = 112 three
- 3 l14
3 l4 r 2
1 r 1

Vocab

Order of Operations

G = groups (identified by an additon or subtraction symbol)

E = exponents

D M = (left to right) divide/multiply

S A = (left to right) subtract/addition


DO NOT use or teach PEMDAS = confusing!!!!!!!

Denominaror

Denominator: tells us the size of each whole or piece.


Example:


4

5 = the denominator

Numerator

Numerator: tells us how many pieces we have of a whole.


Example:


4 = the numerator

5

Standard Form



Example:


2 , 345 , 1,112 , 4 , 300 , 32 , 250

Irrational Numbers



Rational Numbers


Example:


4.12 , x = + 5 , x = + 7 , x2 = 49 , x2 = 25

Trinomial
Binomial
Volumw

Volume = l x w x d


Area

A = l x w (any two "numbers" together)

- generic rectangle

- base 10 recrangle

Zero Bank

Zero Bank: adding any equal number of pairs of positive and negative numbers.

Zero Pairs

Zero Pairs: add a positive and a negative (cancels each other out).

Intergers

Intergers: whole counting numbers

Venn Diagram

Venn Diagram:  sets are represented by shapes; usually circles or ovals. The elements of a set are labelled within the circle. They are especially useful for showing relationships between sets.

Double Bubble

GCF:

(2 x 2 x 2) x 3 x (5 x 5) and (2 x 2) x 5 x (7 x 7) = 20


Example:


#1 2 2 #2

2 2

2 5

3 7

5 7

5


2 x 2 x 5 = 20


LCM:

(2 x 2 x 2) x 3 x (5 x 5) and (2 x 2) x 5 x (7 x 7) =

(2 x 2 x 2) x 3 x (5 x 5) x (7 x 7)


Example:


#1 2 2 #2

2 2

2 5

3 7

5 7

5


(2 x 2 x 2) x 3 x (5 x 5) x (7 x 7)

Upside Down Division

Upside Down Division: is one of the techniques used in Prime Factorization method to factor numbers.




LCM

LCM: Least Common Multiple (bigger numbers)

LCM:

28 and 60 = 420


Example:

28 60

(4) (7) (5) (12)

(2) (2) (6) (2)

(3) (2)


(2)(2)(7)(5)(3)(2)(2)

2 x 2 x 7 x 5 x 3 = 420


GCF or GCD

GCF = Greatest Common Factor (small numbers)


OR


GCD = Greatest Common Divisor (small numbers)

Factor Tree

GCF or GCD:

18 and 30 = 6


Example:

18 30

(9) (2) (3) (10)

(3) (3) (2) (5)

2 x 3 x 3 2 x 3 x 5

2 x 3 = 6 2 x 3 = 6

List

GCF or GCD:

18 and 30 = 6


Example:

Factors of 18 = 1, 2, 3, 6, 9, 18

Factors of 30 = 1, 2, 3, 5, 6, 10, 15, 20

Composite Numbers

Composite Numbers: Divisible by more than 2 factors


Example:


385 = Composite

385 divided by 5 = YES

285 divided by 385 = YES

384 divided by 1 = YES

Prime Numbers

Prime Numbers: Divisible by 1 and itself


Example:


257 = Prime

257 divided by 7 = NO

257 divided by 11 = NO

257 divided by 13 = NO

Base Ten

Unit = 1
Long = 10
Flat = 100
Cube = 1000
Repeats on and on...

UnDevCarLo

1.) Understand the problem
2.) Develop a plan
- your way to solve with pictures, guess & check, equations
3.) Carry out plan
- do the work & solve
4.) Look back- check your work

CCR