Math 156
Properties
Addition
Closure propeties of addition
aEx and bEx then a=b E
Closure propety of adding whole numbers
if aEw and bEw then a+b E w
Communitive property of addition of whole numbers
If aEw and bEw then a+b = b+a
Associative property of whole numbers
aEw bEw and cEw then (a+b)c = a(b+c) or (a+c)b
Identity property of addition of whole numbers
aEw then a+0=a=0+a
Subtraction
Closure property of subtraction of whole numbers
aEw and bEw then (a-b) E w
Communitive property of subtraction of whole numbers
aEw and bEw then a-b=b-a
Identity property of subtraction of whole numbers
aEw then a-0=a= 0-a
Multiplication
Closure property of multiplication for whole numbers
aEw and bEw then abEw
Communitive property of multiplication of whole numbers (changes order)
aew and bEw then ab=ba
Associative propoerty of multiplication of whole numbers (changes grouping)
(a*b)*c =a* (b*c)
Identity property of multiplication of whole numbers
aEw then 1(a)= a b/c 1 is the identity element
Zero property of multiplication
aEw then 0(a)= 0
Distributive property of multiplication over addition and subtraction
aEw, bEw, and cEw -> a(b+c) -> ab+ac
Division
Sequence/ Patterns
Is an ordered list of numbers or events that may be referred to as elements of a sequence, members of the sequence or terms of the sequence.
Arithmetic Sequence
Is a number sequence with a common difference.
Method: a(n)=a1+d(n-)
Geometric Sequence
Is a number sequence with a common ratio.
Helpful: # on the right/ # on the left.
Method: a1(r) to the n-1 power
Reoccurence Sequence
A sequence in which the current term is dependent on the previous term.
Method: b, sub unknown= 2(b, sub last term solved)+ (b, sub the term before last solved term.)
Main topic
Ratios and proportions
proportional (part of a whole) between two different numbers or quantities.
Clocks
Has different module that determine what numbers go around it. They usually want to know what one number is congruent to another number by using a specific Mod. clock.
Ex 12=0 we see if twelve is congruent to zero, which it is when using a mod 12 clock.
Understanding Integers
can be done visually with chips or on a number line
The opposite of the number a is the number that must be added to a to produce an additive identity. a + ??= 0.This is referred to as the opposite of a written as -a.
Arithmetic with integers
Division
We know the number of groups. We need to find the size of groups.
Repeated subtraction
We know the size of groups. We need to find the number of groups.
Properties of Modular Arithmetic
Closure prop. of Addition
Closure prop. of Multiplication
When we add/mult. any two values on the clock, and we get another answer that is on the clock.
EX: 0+4 mod5 = 4
Communitive prop. of Addition
Communitive prop. of Mulitplication
Gives a mirror image across the mult/or addition chart when looking at the diagonal.
EX: a+b mod5 = b=a mod5
Identity of Addition
Identity prop. of Multiplication
When we add/mult. two numbers and ending with the same number you first started with.
EX: a = ? mod5= a
Inverse prop. of Addition
Inverse prop. of Multiplication
When we add/mult. two numbers and end with the number zero (the inverse.)
EX: a + b mod5 = 0
Modles/ Context
Addition
Discrete (set): countities
Characterized by combining two sets of discrete objects
Examples: markers, animals, kids, chairs, fruit
Individually separate and distinct objects
Continuous (number line): measured quantities
Characterized by combining of two continuous quantities
Example: Time, distance, area, volume
Subtraction
Take Away
Characterized by starting with some initial quantity and removing or (taking away) specified amount
Comparison
Characterized by comparison of the relitive sizez of two quantities and determining either how much longer or how much smaller one quantity is compared to the others.
Missing Addend
Characterized by the need to determine what quantity must be added to a specified number to reach some targeted amount.
Multiplication
Repeated addition (Discrete)
Ex: 3 rows of seats with two students in each. How many students altogether?
Repeated addition (continuous)
Is characterized by repeatedly adding a quantity of continuos quantities. A specified number of times.
Area Modle
characterized by a product of two numbers representing the size of a rectangular region, such that the product represents the number of unit sized squares within the rectangular region
Cartesian Product
characterized by finding all possible pairings between 2 or more sets of objects.
Division
Partition (equal product)
Characterized by distributing a given quantity amoung a specified number of groups (partition) and determining the size (amount) in each group (partition)
Measurement (repeated subtraction)
Characterized by using given quantity to create groups or (partitions) of specified size (amount) and determining the number of group (partitions) that are formed
Tradition Algorithm (seperate sheet)
12/2=6 and 12/6=2 (four fact families)
Number Theory
Even
If the number is a multpiple of 2.
Odd
If the number is one more than an even number or one less than an even number.
Fractions
Multiple Interpretations of a fraction
Part-While
2 parts of a whole that was divided into 3 parts
Division
The fraction bar becomes the alternative tool to indiccate division
Copies of a unit fraction (accompaniement to part-while)
2/3 is two copies of the [unit fraction 1/3]
Ratio
Comparing two seperate things ratio of girls to boys is 2 girls/ 3 boys
Rational Numbers
Any number that can be expressed as a quotient of two integers a/b
Operations with Decimals
Addition, subtraction, line up decimals
Multiplication and division solve ignoring decimal till very end then count how many place values over.
how you would say 42.31 is "Forty-two and thirty-one hundreths"
Percents
Ex: What is 12% of 350 people?, 1% of 350 people is 3.5 peoplpe, then you take 3.5 and multi by 12.
Three types of fractions are:
Improper and mixed numbers
7/8 + 1/2
Simplified
6/8 = 3/4
Egyptian
All fractions must be unti fractions 1/n. All unit fractions must be unique. 3/2doesn't = 1/2+1/2+1/2
Division
Partition (long division)
Know the number of groups/partition
Find the size of partition
Repeated subtraction (Divion of fractions)
Know size of group
Find number of groups
Sets
A group of numbers, variable, geometric figures that are using set braces.
Compliment of A
A with a line over the top
Union A intersects Union B
A u B
A Union B
A u B
Examples:
B C A
B = A
B ~ A
B - A
Ways to Record Numbers
Tally
single strokes or tally marks to represent numbers
Egyptian
uses grouping system to represent certain numbers
Babylonian
place value system
Mayan
primarily on 20 with vertical groups
Hindu- Arabic
Base ten system
Roman
uses additive subtractive and multiplicative properties
Problem solving
Understand the Problem
Devise a plan
Pattern
Guess, Check, Revise
Diagram, Picture
Table
Algebraic Symbols
Act it out
Break it down
Work backwards
Impliment the plan
Cusenaire Rods
Used as a mulipulative for factoring and multiples.
Greatest Common Factor
The biggest number that can go into both two numbers
Least Common Multiple
The smallest numbers you can multiple the original number by to get the remaining total the same.
Set Relationships
a~b is when two sets are equal. Meaning they are equivalent to each other
XnY=X is when elements in X must be in Y too.
XnY= XuY If only elements in X and Y and the only elements that are in common and X’s and Y’s elements intersecting are the same, then X and Y are equivalent to each other
one to one correspondence: for each element there is an element of set B to match it with no extra elements and no repeated use of an element.
Methods
Lattice
adding using two four digit numbers
Low stress
list of single digit numbers being added together
Scratch
series of addition only using two digit numbers
Any Column first
large numbers with the same amount of digits being added together
Left to Right
the one that emphasizes place value when you start on the left, add numbers in the first column together then write it down with the place value represented.
Multiplication
Partial product
lattice method
Divisibility
Whole number a is divisible by whole number b if, and only if there exisists a third whole number c.
b is a factor of a, b is a divisor of a, a is a multiple of a, and a is divisble by b
Cuisenaire Rods
Factoring
GCF
Greatest Commmon Factor
The biggest number that goes into all of the comparing numbers.
Multiples
LCM
Least Common Multiple
Smallest multiple that is divisble by all of the comparing numbers.
Ratio, proportions, and reasonings
Ratios
May look like a fraction
Comparing two quantities regardless of whether the units are the same. If units happen to be different this is referred to as a ratio.
Quantitive Relationship
SHowing the number of times one contains or is contained witrhin another value.
Proportion
Are when two ratios are equal
ex: a/b = c/d
Analogy a is to b as c is to d.
Ex: a:b as c:d
Proportional Reasoning
Absolute reasoning and relative reasoning
Rational Numbers
Quantities and knowing how they change
Relative thinking
Ratio Sense
knowing how to use them
Utilizing
Recognizing and comaparing units