Kategorier: Alle - decimals - fractions

af Isabella DiFatta 2 år siden

112

Elementary Mathematics (MTE280)

The content delves into fundamental concepts of elementary mathematics, focusing on decimals and fractions. It explains the representation and conversion of decimal values, such as converting between tenths, hundredths, and thousandths.

Elementary Mathematics (MTE280)

Elementary Mathematics (MTE280)

Week 6

Test 1

Week 5: Subtraction, Multiplication and Division Algorithms

Division Algorithms

8 = dividend

_________ 2 = divisor

2 l 8 the answer = qoutient


8 / 2 = 4 R0


Division Algorithms

  1. Standard
  2. Place Value
  3. Alternate Algorithm



*** Refer to notebook on how to do these.

Multiplication Algorithms

Multiplication Algorithms

  1. Standard
  2. Place Value
  3. Lattice



*** Refer to notebook on how to do these.



Subtraction Algorithms

7 minuend

-3 subtrahend

----

4 difference


Subtraction Algorithms

  1. American Standard
  2. European/Mexican
  3. Reverse Indian
  4. Left-to-Right
  5. Integer Subtraction
  6. Expanded Notation


*** Refer to notebook on how to do these.

Week 4: Four Operations: Concepts & Principals + Addition Algorithms

Multiplication

Multiplication (aka groups of things)




Arrays


---------} #2

________________

l 0 0 0 0 0 0 0 l l

l 0 0 0 0 0 0 0 l l

l 0 0 0 0 0 0 0 l l #1 3 x 7 = 0

l 0 0 0 0 0 0 0 l l

l 0 0 0 0 0 0 0. l l

l 0 0 0 0 0 0 0 l V

________________

Subtraction

Subtraction




Subtraction Algorithms

  1. 
Addition

Addition (aka putting things together)





Addition Algorithms

  1. American Standard - should be the last step
  2. Partial Sums - emphasizes place value, right to left
  3. Partial Sums (b) - adds them by actual place value, right to left
  4. Left-to-Right - emphasis on place value, kids read left to right
  5. Expanded Notation - emphasis on place value, separate by values, the BEST way to start teaching addition
  6. Lattice - just for fun. Not in traditional textbooks


Week 3: Numeration Systems & Expanded Notation

Base-5 System

BASE-5 SYSTEM


Australians use the Base-5 System because there are 5 fingers on a hand


The place values differ from Base-10


Digits used: 0,1, 2, 3, 4, 10(base 5), 11(base 5), 12(base 5), 13(base 5), 14(base 5), 20(base 5)


How to convert Base-5 to Base-10:


232 (base 5) = (2x25)+(3x5)+(2x1)

232 (base 5) = (2x5^2)+(3x5^1)+(2x5^0)

232 (base 5) = 50 + 15 + 2

232 (base 5) = 67



The video shows a much faster, straight forward way to convert without showing as much work. But, it shows what the thinking process should be while converting

Expanded Notation

Expanded Notation




the simple definition is to break down or expand numbers.


For example in Base-10:


375 = 300 + 70 + 5

375 = (3x100)+(7x10)+(5x1)

375 = (3x10^2)+(7x10^1)+(5x10^0)


Base-10 System

BASE-10 SYSTEM



In the US, we use the Base-10 system (also referred to as a decimal or positional system)



Numbers always relate to each other on a 1-10 relationship


The spot where a number is placed indicates the number's value


When you move to the left, the number gets bigger by 10 times


When you move to the right, the number gets smaller by 10 times


For example:

375



The same applies for different units such as decimals, money, miles, etc.

Week 2: Review of Polya's Rules & problem solving practice

Review of Poyla's 4-step problem solving process

POLYA'S RULES



Step 1: Understand the problem.

Step 2: Devise a plan (translate).

Step 3: Carry out the plan (solve).

Step 4: Look back (check and interpret).


This week we solved more problems while applying this method. The biggest thing I took away from this week is that MULTIPLICATION tables are the key to solving a lot of problems!


Our professor had us start off as doing problems the "hard" way, then at the end of class revealed the "easy" way. It was very helpful to start our problem solving without having the easier method so that we could understand how things are broken down and how different students could interpret problems differently.

Week 1: Introductions & Polya's Rules

Polya's 4-step problem solving process

POLYA'S RULES



Step 1: Understand the problem.

Step 2: Devise a plan (translate).

Step 3: Carry out the plan (solve).

Step 4: Look back (check and interpret).



We solved a few problems in class using these steps. Multiple students would go up to the board and write out how they solved problems to show different ways of interpreting the problems.

Introduction to the class / syllabus review

INTRODUCTION



The syllabus includes just about all the information for this course that I could ever need. It includes contact information, policies, assignments, and information about the course itself.


The syllabus can be found on canvas.

Week 16

Final Test

Week 15

Multiplication & Division problems

+3 x -2 = -6 (-)(-)(-)(-)(-)(-) **3 groups of -2



+6 / 2 = +3 (+)(+)(+)(+)(+)(+) ** 3 groups of 2 in 6

Subtraction problems

+5 - -1 = +4 (+)(+)(+)(+)(+) - (+) = (+)(+)(+)(+)





-5 - +1 = -6 (-)(-)(-)(-)(-) - (+)(-) = (-)(-)(-)(-)(-)(-) **cross out (+)

Addition problems

-5 + -1 = -6 (-)(-)(-)(-)(-) + (-) = (-)(-)(-)(-)(-)



-5 + +1 = -4 (-)(-)(-)(-)(-) + (+) = (-)(-)(-)(-) **cross out (+) & one (-) because it is a zero pair

Integers

Integers are positive and negative numbers.



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


-4 -3 -2 -1 0 1 2 3 4




Example:

+5 + +1 = +6 (+)(+)(+)(+)(+) + (+) = (+)(+)(+)(+)(+)(+)

Week 14

Problem solving with decimals and percentages



Week 13

Word problems


Problem solving with percentages

Pay attention to the wording of a problem - it will tell you what you need to solve for.


  1. 9/25 students voted for Marina, what percentage voted for Marina?

25n/25 = 100 x 9/25



n = 100 x 9 / 25


36% of students voted for Marina

Week 12

Test 2

Week 11

Decimal Places

3 7 5 . 3 2

100's 10's ones 1/10 1/100




3/10 is 3 dimes


3/10 = 0.3 = 0.30


0.8 = 8/10 "eight tenths"


0.123 = "123 thousandths"


0.003 = three thousandths


72/100 = 0.72


31/1000 = 0.031


0.83 = 83/100


5/6 = 5 divided by 6 (do long division) = 0.83 (3 repeating)

Week 10

Problem solving with fractions

In order to successfully teach children how to problem solve with fractions, you HAVE to draw pictures!


Each fraction of a whole is equal in value.


Example:


If **** represents 2/7 of the whole, draw what the whole looks like.


** = 1/7

**** = 2/7

****** = 3/7

******** = 4/7

********** = 5/7

************ = 6/7

************** = 7/7

Week 9

SPRING BREAK

Week 8

Dividing & multiplying fractions

Multiplying fractions


  1. Multiply ACROSS


EX: 1/3 X 1/8 = 1/24




Dividing fractions


  1. Keep
  2. Change
  3. Flip


EX: 2/3 divided by 4/5


  1. Keep 2/3 the same
  2. Change division sign to multiplication sign
  3. Flip 4/5 to 5/4
  4. Solve


2/3 X 5/4 = 10/12

Adding & subtracting fractions

Adding fractions with common denominators:


1/4 + 2/4 = 3/4


2/5 +2/5 = 4/5


3/8 + 4/8 = 7/8


** add the numerators, don't change denominator.





Subtracting fractions with common denominators:


5/7 - 2/7 = 3/7


9/10 - 1/10 = 8/10


** subtract the numerators, don't change denominator.






If the denominators aren't the same?


  1. Find a common multiple for the denominators.
  2. Multiply the fraction by one


EX:


1/4 + 1/6


  1. Common multiple for denominators: 12
  2. Figure out what each denominator needs to be multiplied by in order to become 12
  3. Multiply 1/4 by 3/3 (1)
  4. Multiply 1/6 by 2/2


ANSWER: 3/12 + 2/12 = 5/12

Fractional parts & simplifying fractions

Fractional parts are equivalent parts.







To simplify fractions, you need to:

  1. Find a common factor
  2. Divide by 1


** The bigger the common factor, the less steps you will have to simplify a fraction


EX:


25/100


  1. Find a common factor: the greatest common factor is 25
  2. Divide by 1: DIVIDE 25/100 by 25/25


ANSWER: 1/4

What is a fraction?

Models:

  1. Set (group of things)



Fraction:

  1. Part-Whole
  2. Quotient
  3. Ratio


Week 7

Prime Factorization

All prime numbers 1-60:

2,3,5,7,11,13,17,19,23,29,31,37,41,43,47,53,59


Best ways to factor:


Use the factorization tree OR list method to find the Greatest Common Factor (GCF) and Least Common Multiple (LCM)



Factors

24: 1,2,3,4,6,8,12,24

42: 1,2,3,6,7,14,21,42

39: 1,3,13,39

136: 1,2,4,8,17,34,68,136

91: 1,7,13,91

60: 1,2,3,4,5,6,12,15,30


Prime numbers: #'s that have only 2 factors - 1 and itself

Composite numbers: #'s that have more than 2 factors


Divisibility

A is divisible by B if there's a number C that meets this requirement.

c x b = a

ex: 10 is divisible by 5 2x5=10


Divisibility Rules


Ending:

a # is divisible by 2 if it ends with..... 0,2,4,6,8

a # is divisible by 5 if it ends with..... 0,5

a # is divisible by 10 if it ends with..... 0


Sum of digits:


Last digits:


By 7:


By 11:

---> if you double, you subtract

---> if you chop off, you add