Categorii: Tot - division - algorithms - subtraction - multiplication

realizată de Janel Stephens 7 ani în urmă

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MTE 280 Investigating Quatity

This text covers various mathematical concepts and techniques used in number theory and arithmetic operations. It begins by explaining the rules of divisibility for numbers 2, 3, 4, 5, 6, 8, 9, and 10, detailing the specific conditions under which a number can be considered divisible by these values.

MTE 280 Investigating Quatity

MTE 280 Investigating Quatity

Fractions

Addition:Use the are, set, or linear model


Subtraction: Use the are, set, or linear model (cross off pieces to show that you are taking them away)


Multiplication: Usually use the area model (although you can use set and linear model but you probably wont have a fun?easy time with that)


*1/2 x 3/4 (1/2 of a group of 3/4)


Division: Usually use the linear model (although you can use set and linear model but you probably wont have a fun?easy time with that)


*For addition and subtraction you need to make the denominators the same number so you create equivalent fractions

Divisibility

Number Theory

Divisibility Test


A number is divisible by 2 if the last digit is 0, 2, 4, 6 or 8.


A number is divisible by 3 if the sum of the digits is divisible by 3.


A number is divisible by 4 if the number formed by the last two digits is divisible by 4.


A number is divisible by 5 if the last digit is either 0 or 5.


A number is divisible by 6 if it is divisible by 2 AND it is divisible by 3.


A number is divisible by 8 if the number formed by the last three digits is divisible by 8.


A number is divisible by 9 if the sum of the digits is divisible by 9.


A number is divisible by 10 if the last digit is 0.


Factor Rainbow


A factor rainbow is a rainbow-shaped diagram that factors of a number in pairs


Property Types

Zero Property

*Zero Property of Multiplication: Anything multiplied by zero is zero

*a x 0 = 0

Distributive Property

*Distributive Property of multiplication over Addition/Subtraction: ex. 5(3+4) = 5 x 3+5 x 4

*Distributive Property of Multiplication over Subtraction for Whole Numbers: a(b - c) = ab - ac

*Distributive Property of Multiplication over Addition for Whole Numbers: a(b+c) = ab + ac

*Distributive Property DOES NOT work for division

Identity Property

*Property for Addition AND Multiplication

*Addition: a+0=a
*Multiplication: a x 1 = a = 1 x a

Addition: When adding a zero to any number, the sums stays the same

Multiplication: When multiplying 1 to any number, the quotient stays the same

Closure Property

*Works for Addition AND Multiplication

*Addition: If you add any two whole numbers, the sum will be a whole number

*Multiplication: If you multiply any two whole numbers, the quotient will be a whole number

Associative Property

*Property for Addition AND Multiplication

* a+(b+c) = (a+b)+c OR a x (b x c) = (a x b) x c

Addition: When adding three or more numbers, the grouping of the numbers will not change the sum

Multiplication: When multiplying three or more numbers, the grouping of the numbers will not change the quotient

Commutative Property

*Property for multiplication AND addition

*(a+b)=(b+a) and (a x b)=(b x a)

*Addition: Changing the order of the addends will result in the same sum

*Multiplication: Changing the order of the factors will result in the same sum.

Addend: Numbers in an addition problem

Factors: Numbers in a multiplication problem

Problem Types

*Partition: Diving a group of numbers into smaller equal groups

*Missing Factor: Using a related multiplication fact to find the answer

*Repeated Subtraction: Subtracting the number that we want to divide by its dividend the same number of times as the quantity of the dividend to reach the final answer


*Repeated-Addition: Putting equal-sized groups together to reach a quotient

*Rectangular array and Area Model: Objects are arranged with the same number of objects in each row

*Cartesian: Creating a tree diagram to show numerous outcomes of the product


*Take Away: Starting with an initial quantity and removing a specified amount

*Missing Addend: The need to figure out what quantity must be added to a specified quantity to reach a target amount

*Comparison Problem: Comparison of the relative sizes of 2 quantities to determine how much smaller or larger one is than the other

*Linear: On a number line using arrows to show a change

*Set Model: The combining of two sets of discrete objects (individually different and distinct objects)

*Linear/Number line Model: Combining two continuous quantities (measured quantities like time, distance, quantity, etc). Shown on a number line to show the change.

Algorithms

* Partial Products

*Lattice

*Using base 10 blocks to create a concrete model for subtraction.

*Equal-Additions: The difference between two numbers does not change if the same amount is added to both numbers

*Trade First

*Counting Up

*Partial Differences

*Children use manipulatives, which are physical items that they can interact with to create their own algorithms.

*Left-to-Right: Adding from left to right. Adding the larger pieces then the smaller ones.

*Lattice: Add single digit numbers by place value on top to the single digit numbers on bottom then add the sums from the diagonals.

Scratch: Adding complicated additions by adding only two single digits

Expanded Notation: Separating a larger number into smaller components that still equal the same number when added

Compensation: Adding a number that does not exist

Partial Sums: Sum of part of the sequence

*Given any whole numbers, a and b with be not equaling zero, there exist unique whole numbers q (quotient) and r (remainder) such that a = bq + r with 0 < r < b.

*Partial Quotients

*Column Division

Decimals

Operations

Addition: Line up the decimals

Subtraction: Line up the decimals


Multiplication:


Division:

Use base 10 blocks


Comparing


Terminating: Comes to an end

Non-Terminating: Repeats


Integers

Subtraction
Addition
Division
Multiplication

Number line Model: used to represent positive and negative quantities, and the number line model can illustrate properties of signed arithmetic.


Pattern Model: The first digit of the sequence stays consistent while the digit being added changes each time the pattern is repeated, until reaching the opposite of the sum


Charged Field Model: Positive and negative charges are used just like a chip model, and the field has 0 charged if it has the same number of positive and negative charges.


Chip Model: Positive integers are represented with black chips and the negative charges are represented with red chips. A red chip can neutralize a black chip

Concepts

Integer Concepts:



Chip Method: When modeling integers, we can use colored chips to represent integers. One color can represent a positive number and another color can represent a negative number


Number Line: A number line can be used to represent positive and negative quantities, and the number line model can illustrate properties of signed arithmetic.


Absolute Value: The absolute value of x, denoted "| x |" (and which is read as "the absolute value of x"), is the distance of x from zero.

Digits

Digits: Set of singular numbers --> (1,2,3,4,5,6,7,8,9)

* Digits are the foundation of ALL numbers

Base Systems

Base 12

*System primarily used by African tribes

*"1..2..3..4..5..6..7..8..9..x..3..10"

*3(Backwards 3): El

*x: Dec

*10 is ACTUALLY 12 in this sytem

Base 5

* Contains 5 digits

*"0..1..2..3..4"

Base 2

*Known as the binary system

*Contains the numbers 1 & 2

*"0..1.."


Base 10

Hindu Arabic- Known as the U.S. version of the base system

*There are 10 digits in this system

*System goes up to number 9 --> (0,1,2,3,4,5,6,7,8,9)


Algorithms Vs. Strategies

Strategy: A method or trick to help students comprehend math


Algorithm: A step-by-step solution


Strategies:


Decomposition: Separating numbers into their components (To divide a number into smaller parts


Comprehension: Understanding concepts, operations, and relations


Open Number line: Visual representation for recording and sharing students' thinking strategies during the process of mental computation


Base 10 Blocks/Pictures: Strategy used for visual representation while working through math problems such as: addition, multiplication, subtraction, division, etc. This strategy greatly helps children who cannot understand how to work through a problem fully as the blocks or pictures allows them to visually see the quantity of a number


Algorithms


Partial Sums: The sum of part of a sequence (a set of numbers that is in order)


Expanded Notation: Writing a number to show the value of each digit


Standard Notation: Number is completely written out using numerical digits