Категории: Все - sequence - numeration - problem - sets

по Kandis Schwan 10 лет назад

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MAT156

Teaching mathematics effectively involves understanding various numeration systems and problem-solving processes. The numeration system includes components like units, longs, and flats for base 10 counting, as well as Roman numerals where specific letters represent values, and combinations of these can create numbers.

MAT156

Tips on Teaching Math            MAT156

Chapters 3.1, 3.2, 3.3, 3.4 and 4.3

4.3 Functions
Relations: Every function is a relation, but not every relation is a function.
Ways to represent functions:

As Graphs: Horizontal- inputs Vertical- outputs

As Tables and Ordered Pairs: 0 1 1 3 2 5 3 7 4 9 (0,1), (1,3), (2,5), (3,7), (4,9)

One input cannot have more than one output. X cannot be the same as another x, but y can be the same as another y

Function? (1,2), (1,3), (2,3), (3,4) NO, 1 INPUT is used twice.

As Arrow Diagrams: Used to examine whether a correspondence represents a function. Domain Range 0 1 1 4 2 7 3 10 Yes, a function 1 2 2 4 3 No, since element 1 is paired with 2&4

As Equations: f(0)= 0+3=3 f(1)= 1+3=4 f(3)= 3+3=6

As Machines: x f(x) 0 3 1 4 3 6 4 7 6 9

As Rules: 1 3 0 0 4 12 Rule= nx3

A function is a relationship that assigns exactly ONE output for each input.
3.4 Algorithms for Whole-Number Multiplication and Division
Division of Algorithms:

Always multiply your quotient times the divisor to get the dividend to check your answer.

Instruction for "long division": Divide Multiply Subtract Check Break Down

"Does McDonalds Sell Cheese Burgers?" DMSCB

Multiplication Algorithms:

Multiplication with Two-Digit Factors: 2 3 x 1 4 (10+4) ________ 9 2 (4X23) + 2 3 0 (10X23) ___________ 3 2 2

Single Digit times two digit: 1 2 10+2 x 4 ---> x 4 _____ ______ 4 8 40 + 8

3.3 Multiplication and Division of Whole Numbers
Order of Operations: PEMDAS Parenthesis Exponents Multiplication or Division (LEFT TO RIGHT) Addition or Subtraction (LEFT TO RIGHT)
Division by 0 or 1:

n divided by 0 is undefined 0 divided by n is 0 0 divided by 0 is undefined

Inverse Operations:

Division is the inverse of multiplication

Division Algorithm:

a=bq+r with 0< or equal to r

Repeated subtraction model: 18 divided by 6 could be shown as 18-6=12-6=6-6=0

KEY VOCAB: (a/b)=c a is the dividend b is the divisor c is the quotient

Missing- Factor Model: 3xc=18. Using multiplication we know that 3x6=18, therefor c=6

Set (Partition) Model: Set up a model of the total number of items in the problem then partition them into sets. ex.) 18 cookies divided by 3 would be 3 sets of 6 cookies

Properties of Multiplication:

Closure: axb= whole number Commutative: axb=bxa ex.) x+5=5+x Associative: (ab)c= a(bc) ex.) 9(xy)=(9x)y Distributive: a(b+c)=ab+ac or a(b-c)=ab+-ac ex.) 8(x-2)= 8x-16 Multiplication Identity of One: bx1=1xb Multiplication by 0: 0xb=bx0=0

Cartesian-Product Model: Use of a tree diagram to solve multiplication problems.

Be aware of how multiplication is modeled: AxB, A(B), AB where A and B are the factors and AxB is the product

Repeated Addition Model: 3+3+3+3=12

3.2 Algorithms for Whole-Number Addition and Subtraction

Use base-ten blocks to show adding and taking away AFTER a manipulative

ALWAYS START WITH A MANIPULATIVE!!
3.1 Addition and Subtraction of Whole Numbers

Models:

Number line

Comparison Model: Susan has 3 blocks Timmy has 8 blocks

Missing Addend: 3+__=8 --> Put in 3 blocks plus__=8 --> Number line --> Fact families --> Cashiers- Movie costs $8, you paid $10 which means 8+2=10

Take-Away: You have 8 blocks, take away 3

Subtraction is the inverse of addition

Basic Addition Facts:

Counting Back: 9+7= 9 is one less than 10 which equals (10+7)-1=16

Making 10 then adding leftovers: 8+5= (8+2)+3=13

Doubles: 3+3=6 3+4= by 3+3=6 plus one more =7

Counting On: 4+2=4,5,6

Addition Properties: Closure: a+b= whole number Commutative: a+b=b+a Associative: (a+b)+c= a+(b+c) Identity: a+0=a
Number Line (Measurement) Model: ALWAYS START AT ZERO
KEY TERMS: numbers a+b are the addends a+b is the sum
Set Model: Set A n(A)= {a,b,c,d} Set B n(B)= {e,f,g} n(A)+ n(B)= {a,b,c,d,e,f,g}= 4+3+7= n(AuB)

Chapters 1.1, 1.2, 2.1, 2.2/2.3

2.2 and 2.3 Sets
Finite vs. Infinite

Infinite if anything other than finite

Finite if its cardinality is 0 or a natural number

Equivalent Sets:

Ex.) A= {p,q,r,s}     B= {a,b,c} C= {x,y,z}       D= {b,a,c} A=C  False A~C  False A=B  False B~D  True C cannot equal D  True

Do NOT confuse "equal" with "equivalent"

Ex.) A= (p,q,r,s) B= (a,b,c) C= (x,y,z) D= (b,a,c) Set A and B are not equivalent and not equal. Set B and C are equivalent, but not equal.

Two sets A and B are equivalent (A~B) if and only if there exists a one-to-one correspondence.

One-to-One Correspondence:

If elements of sets P and S can be paired so there is one element of P for each of S and one element of S for each of P then P and S are in one-to-one correspondence.

Each element is only listed once
Order is NOT important
The objects that belong to the sets are called members or elements
A set is any  group or collection of objects
Base 5
Ex.) 1 0 3 0 base 5= 1x5 to the 3rd power (1x125)+0x5 to the 2nd power+3x5 to the 1st power (3x5)+0x5 to the zero power...125+0+15+0=140
5 zero power=1 5 first power=5 5 second power=25 5 third power=125 5 fourth power=625 5 fifth power=3125, etc.
2.1 Numeration System
Base 10

Anything to the zero power is one

Ex.) 10 base 6= 100,000

Read as 1,2,3 base 10

No base noted means the number is base 10

Number of power= how many zeros used

Ex.) MDCCLXXIII= 1000+700+70+3
I=1 V=5 X=10 L=50 C=100 D=500 M=1000 IV=4 (5-1) IX=9 (10-9) XL=40 (50-10
Roman Numeral System
10 block breakdown: Unit =1 Long=10 Flat=100
1.2 Patterns
Fibonacci Sequence

1,1,2,3,5,8,13,21,34,55,89

Sum of first two numbers equal third number

Geometric Sequence

an= 3x2^(10-1) an= 3x2^9 an= 3x512 10th term= 1536

Ex.) 3,6,12,24... 10th term

a (little n)= a (little 1) x r ^ (n-1)

Uses multiplication of the ratio

Arithmetic Sequence

an=1+(20-1)2 an=1+(19x2) an= 1+38 an=39

Ex.) 1,3,5,7,... 20th term

a (little n)=an=a (little one)+ (n-1)d

Must have common number pattern!

1.1 Problem Solving
Skipping Numbers

103+1=2n 104=2n 104/2=52 52x104=5408 5408/2=      2704

Ex.) 1+3+5+7...+103

Gauss's Approach to Find the Sum

= 499,500

999 Sums of 1000= 999,000/2           999x1000

S=1      2      3      4      S=999   998  997   996 ___________________ 2S= 1000

Ex.) 1+2+3+4...+999

4 Step Problem Solving Process:      1. Understand the Problem      2. Devise a Plan      3. Carry Out the Plan      4. Looking Back (CHECK)

Chapters 6.1, 6.2, 6.3, 7.1, 7.2, and 7.3

7.3 Nonterminating Decimals
Ways to convert some rational numbers to decimals:

OR numerator divided by denominator point zero, zero, zero 7/8 = 8.000/7

7/8 = 7/ (2^3) = (7x(5^3))/ ((2^3)(5^3))= 875/1000= 0.875

7.1 and 7.2 Introduction and Operations on Decimals
Dividing Decimals:

1.2032/ 0.32 becomes 120.32/ 32

Scientific Notation:

0.000078= 7.8 x 10 ^(-5)

93,000,000= 9.3 x 10^7

Algorithm for multiplying decimals:

4.62 x 2.4 = 462/100 x 24/10 = 462/(10^2) x 24/(10^1) = (462 x24)/ ((10^2) x (10^1)) = 11088/ (10^3) = 11.088

Algorithm for addition and subtraction of terminating decimals:

2.16 1.73 _____ 3.89

Ordering Terminating Decimals: Change decimal by adding place value such as 0.36 and 0.9 change to 0.36 and 0.90 to ease in ordering decimals.
Terminating Decimals: Decimals that can be written with only a finite number of places to the right of the decimal point.
Convert to decimals: 25/10= (2 x 10+5)/10 = (2x10)/10 + 5/10 = 2 + 5/10 = 2.5
6.3 Multiplication and Division of Rational Numbers
Multiplication with Mixed Numbers:

Use Distributive Property

Use Improper Fractions

Properties of Multiplication of Rational Numbers:

Multiplication Property of Zero: (a/b) x 0 = 0 = 0 x (a/b)

Multiplication Property of Inequality: (a/b) > (c/d) and (e/f)>0, then ((a/b) x (e/f)) > ((c/d) x (e/f))

Multiplication Property of Equality: (a/b) x (e/f) = (c/d) x (e/f)

Multiplicative Inverse: (a/b) x (b/a) = 1 = (b/a) x (a/b)

Multiplicative Identity: 1 x (a/b) = a/b = (a/b) x 1

Distributive Prop of Multiplication Over Addition a/b ((c/d) + (e/f)) = ((a/b) x (c/d)) + ((a/b) x (e/f))

a/b x c/d = (a x c) / (b x d)
6.2 Addition, Subtraction, and Estimation with Rational Numbers

Greater Than and Less Than:

a/b < c/d if c/d - a/b > 0 c/d > a/b if and only if a/b < c/d

a/b - c/d = (ad-bc)/ bd

a/b - c/d = e/f

Rational Numbers Properties:

For any rational number a/b, there exists a unique rational number -(a/b) called the additive inverse of a/b

a/b + c/d = (ad)+ (cb)/bd

Addition of Rational Numbers with Like Denominators:

a/b + c/b= (a+c)/b

Number-line Model

Area Model

6.1 The Set of Rational Numbers
Denseness of Rational Numbers:

1/2 and 2/3 = 3/6 and 4/6

Ordering Rational Numbers:

Rewrite fractions with the same positive denominator

Equality of Fractions:

Rewrite both fractions with a common denominator

Rewrite both fractions with the same LCM

Both fractions to the same simplest forms

Simplifying Fractions:

A rational number a/b is in the simplest form if b>0 and GCD (a,b)=1; that is, if a and b have no common factor greater than 1 and b>0

Equivalent or Equal Fractions:

Can be found from dividing n/n into a fraction such as 12/42= 2/7x6/6=2/7

Let a/b be any fraction and n a nonzero integer. Then a/b= an/bn

The value of the fraction does not change if its numerator and denominator are multiplied by the same nonzero integer

Represent the same number on the number line

Proper Fraction: Numerator is smaller than the denominator Improper Fraction: Numerator is larger than the Denominator
Uses of Rational Numbers:

1. Division problem or solution to a multiplication problem 2. Partition, or part, of a whole 3. Ratio 4. Probability

a/b, a is the numerator and b is the denominator

Chapters 5.1, 5.2, 5.3, 5.4, and 5.5

5.5 GCF and LCM
Least Common Multiple:

Use same methods as used for GCF

Definition: The least natural number that is simultaneously a multiple of a and multiple of b

Greatest Common Factor:

Ladder Method

Prime Factorization Method: 180= 2x2x3x3x5= ((2^2) x3) 3x5 168= 2x2x2x3x7= ((2^2)x 3)2x7 Thus the common prime factorization is (2^2)x3=12

The Intersection of Sets Method: List all members of the set of positive divisors of both integers, then find the set of common divisors and pick the greatest element in that set.

Definition: The greatest number that divides into both a and b

5.4 Prime and Composite Numbers
Composite:

Definition: Numbers in which there are more than 2 factors or positive divisors

Prime:

Prime Factorization:

Sieve of Eratosthenes: method of identifying prime numbers

Number of Divisors: How many positive divisors does __ have?

Ladder Model: 2 l12 2 l 6 3 l 3 1

Factor Tree

Definition: a factorization containing only prime numbers

Composite numbers can be expressed as products of 2 or more whole numbers greater than 1

Definition: Numbers in which there are only 2 factors or positive divisors

5.3 Divisibility
Divisibility Rules: A number is divisible by...

11 if the sum of the digits in the places that are even powers of 10 minus the sum of the digits in the places that odd powers of 10 is divisible by 11

10 if the last digit is 0

9 if the sum of the digits is divisible by 9

8 if the last 3 digits are divisible by 8

6 if it is divisible by 2 and 3

5 if the last digit is 0 or 5

4 if the last two digits are divisible by 4

3 if the sum of the digits is divisible by 3

2 if the last digit is even

5.2 Multiplying and Dividing Integers
-3^4= -81 HOWEVER (-3)^4= (-3)(-3)(-3)(-3)= 81
Order of Integers:

x+3<-2 x+3+-3<-2+-3 x<-5 (-6,-7,-8,...)

Order of Operations:

PEMDAS

Division:

The quotient of 2 negative integers is positive The quotient of a negative and positive integer is a negative

Multiplication:

Properties: Closure Commutative Associative Multiplicative Distributive Zero Additive Inverse: (2x3) is -(2x3) thus (2x3) +(-2)(3)=0

Same models as those used for both addition and subtraction of integers

5.1 Adding and Subtracting Integers
Subtraction:

Properties: CANNOT do commutative or associative

Same models as those used for addition

Addition:

Properties of Integer Addition: a.) Closure b.) Commutative c.) Associative d.) Identity

Absolute Value: The distance between the number and zero The absolute value of both 4 and -4 is 4 ALWAYS POSITIVE OR ZERO!

Pattern Model: 4+3=7 4+2=6 4+1=5 4+-4=0 4+-5=1 4+-6=-2

Number Line Model: ALWAYS START AT ZERO

Charged Field Model: (+) and (-) charges

Chip Model: Black= positive Red= Negative