Категории: Все - division - models - subtraction - multiplication

по Rachael Mertes 2 лет назад

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Elementary MathematicsRachael Mertes

The document explores foundational concepts in elementary mathematics, focusing on units of multiplication, division, and whole number subtraction. It provides various methods and models for understanding multiplication, including partial products, front-end multiplication, the area model, and repeated addition.

Elementary MathematicsRachael Mertes

Elementary MathematicsRachael Mertes

Unit 2
6.1

Comparing Fractions: 3/4 > 5/16: closer to a whole

Youtube: https://youtu.be/dIc_CD6KTuo

Simplifying Fractions: 60/210= 6*10/21*10=6/21= 2*3/7*3= 2/7 (simplified fraction)

Equivalent Fractions: 2 fractions that can be simplified to equal one-another ex: 3/6= 9/18

Improper fraction: a/b where it is greater or equal to 0 ex: 6/4

Proper fraction: rational # where a/b is less than 1 ex: 3/4

Set Model: https://youtu.be/E0KQauFeJo8

Number Line: https://youtu.be/fLY9yRdBObQ

Bar Model: https://youtu.be/5NsUu9s_yGc

denominator: the number below the line in a common fraction; the whole

numerator: the number above the line in a common fraction showing how many of the parts indicated by the denominator are taken

rational #: a/b

5.2

Ordering Integers

equal to: a=b

more than: a>b

less than: a

Integer Division

Using Chips and Number Line: https://youtu.be/lDR-B_OhUQo

Integer Multiplication

Patterns of Multiplication

zero: a*0=0=0*a

identity: a*1=a=1*a

distributive:a(b*c)= a*b+a*c

associative: (ab)c=a(bc)

communicative: ab=ba

closure: ab is a unique umber

Chip Model & Number Line Representation https://youtu.be/fW3FWuLfpFc

5.1 Integer

Properties of Integer Addition:

Identity: 0+a=a=a+0

Associative: (a+b)+c=a+(b+c)

Communicative Property: a+b=b+a

Closure: a+b is a whole unique number

Number Line Model: https://youtu.be/3LUTYhmltQY

Chip Model: https://youtu.be/_77vO0uzBfA

Absolute Value: the distance between the point corresponding to an integer and zero. ex: |-3| = 3

Integer: a whole number that is not a fraction

4.3

Slide Method: https://youtu.be/IM7ToCYo-_A

Least Common Multiple LCM

of 2 whole numbers a& b is the least non-zero multiple of both a&b

Greatest Common Factor GCF

Prime Factorization Method: 180 & 168 ex: GCF 180 & 168180: 2*2*3*3*5= 2^2*3(3*5)168: 2*2*2*3*7= 2^2*3(2*7)GCF= 2^2*3 or 12

of 2 whole numbers a &b not both 0, is the greatest whole # that divides both a&b

4.2

Prime Factorization: containing prime and composite numbers to find, where we rewrite the #s as a product of two whole numbers, where we continue to process until the numbers/factors are prime.

Youtube: https://youtu.be/tW97UU01ShY

ex: 260= 26*10= (2*13) (2*5)= 2*2*5*13= 2^2*5*13

Composite Number: any whole number that has factors that make up the whole. ex: 4,6,8,10,12 etc

Prime Numbers: any whole number that is only divisible by 1 and itself. ex: 1,2,3,5,7,11,13 etc

Factorization: breaking a # down into smaller #s, that when combined back together gives you the original #

4.1 Divisibility

Odd #: a whole # with a remainder of 1 when divided by 2

Even #: a whole # that has no remainder when divided by 2

Divisibility Rules:

Youtube: https://youtu.be/E4yzE5NumV8

10: a number is divisible by 10 when the units digit ends in a 0 ex:100 or 250 or 490

9: a number is divisible by 9 if the sum of the digits of the number is divisible by 9 ex: 998

8: a number is divisible by 8 if the last 3 digits represent a number divisible by 8 ex: 234800

6: both rules for 2 & 3 work, then the number is divisible by 6 ex: 12 (12/2=6 or 12/3=4)

5: a # is divisible by 5 if the units digit is divisible by 0 or 5 (last digit ends in a 0 or 5) ex: 100 or 155

4: a # is divisible by 4 when the last two digits of the number make a # that is divisible by 4 ex: 4520

3: a number is divisible by 3 when the sum of its digits is divisible by 3 ex: 876

2: a # is divisible by 2 only if the units digit is even ex: 542

.

Unit 3
Proportions

Youtube Video: https://youtu.be/wT8tGc-SwKk

Scale Drawing: ratios and proportions: scale= the ratio of the size of the drawing to the size of the object

Unit Rate Strategy: for solving problems involves finding the unit # compared of the 1 ticket to comparing the unit cost

ex: 12 ticket= $15=1=$1.2520 tickets= $23=1=$1.15

Constant Proportionality: x and y are related by equality y=kx or k(y/x), then y is proportional to x+k to the constant of proportionality between y and x

Example: https://docs.google.com/document/d/1m5Li_NSH6CWH6B3OgqMu-c0CfM5MAbqYP3twmmuo0cA/edit?usp=sharing

Ratio Word Problem Ex in

Part to Part: ratio of boys to girls would be 1:3 or teacher to students would be 24(class size): 1 (teacher)

Whole to Part: ratio of all children(whole) to boys(part) is 4:1

Part to Whole: 1:3 boys to girls- ratio of boys(part) to children(whole) is 1:4 ratio

Definition: a/b or a:b where a and are rational numbers is a comparison of 2 quantities

Operations of Decimals:

Dividing Decimals: Ex in https://docs.google.com/document/d/16prYEmOk5CthA6BWWTwYq06CCbtNITChDLYimYKR4DA/edit?usp=sharing

Long Division: https://youtu.be/LGqBQrUYua4

Algorithm for multiplying decimals: if there are n digits to the right of the decimal point in 1 # and m digits to the right of the right of the decimal point in a second #, multiplying the 2 #'s, ignoring decimals, then placing the point so there n+m digit places from the right of the decimal point of the product

Multiplying Decimals using the Grid model: Ex https://docs.google.com/document/d/1rcqLDmTGWJdTRJLtC7jzEkHy7y9aj2CJHb6unl6-kMc/edit?usp=sharing

Multiplying decimals using expanded base 10 blocks model: Ex in https://docs.google.com/document/d/1DY2ACD7pCF-BgSESnaqlLOPpodz2KCaEDyLEo8JQtkQ/edit?usp=sharing

2.63 *8.2 21.566

Youtube video for Multiplication: https://youtu.be/Dm028SSei88

Mental Compution:

Breaking and Bridging:1.5 + 3.7 +4.48(1.5+3=4.5) & (4.5+.7=5.2) & (5.2+4=9.2) & (9.2+.48=9.68)

Subtraction: is doen using the grid by representing the first number in grid form, then by taking away the second number.

Ex https://docs.google.com/document/d/12A5k4AWCaVIcGLKU2dlCPJQiM5-ZjnIqPKVvDFDSe74/edit?usp=sharing

Addition: is done by placing the decimal reps of the 2 addends in the same decimal grid. May need to regroup.

Ex https://docs.google.com/document/d/1Y6oTRgnuOuOuLj6nXQahKVGO-wL4XVufRLl8MTE_CIo/edit?usp=sharing

Rational Fractions

Rational Fraction Division

Grouping Model: EX in https://docs.google.com/document/d/1VlcZqwTud3pKK_vNSRqVh1eVV8QWaU99iS2_d7dYCyU/edit?usp=sharing

Unlike Denominators:

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

Equal Denominators:

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

"Invert and Multiply"

https://youtu.be/e1gcBP2TmPk

ex: (2/3)/ (5/7) is equivalent to (2/3)(7/5)

EX in https://docs.google.com/document/d/1HRqwoUUTjGpPNoVFZ9Im2hC75JW8M39RP0nyEStMmIc/edit?usp=sharing

Rational Fraction Multiplication:

YouTube Video: https://youtu.be/mUQbh_chhQQ

Using different models: https://docs.google.com/document/d/1GC1CVPsIkMCS-T6zhgTKf3tldmk4dFu9111-yPtug9U/edit?usp=sharing

Multiplication with Mixed #s : Convert the mixed number into an improper fraction. Then multiply the numerators of the fraction and multiply the denominators of the fraction. Last, onvert it into simplified form if required.

Fundamental Law of Fractions: a/b= (an)/(bn) if b doesn't equal 0 and n doesn't equal 0

Identities:

Distributive: a/b(c/d +e/f) = (a/b)*(c/d) + (a/b)*(c/d-e/f)= (a/b)*(c/d)-(a/b)*(e/f)

Multiplicative: rational number 1 is the unique # where every rational # a/b= 1* (a/b)=(a/b)=(a/b)* 1

Estimating Rational Numbers: estimating fractions to see if they are closest to 1, 1/2, or 0; and in some cases, estimating bigger fractions to see if they would most likely be reduced closest to 0, 1/2, 1/4, 1/3, 3/4, 1, etc. https://youtu.be/UBFyCnSKfBE

Is 52/100 closest to 1, 1/2, or 0?- Closest to 1/2 because 52/100 is closest to 50/100= 5/10=1/2. 52/100 is 2 away from 1/2 vs being 48 away from 1 whole

Addition&Subtraction

Youtube Video: Start at 2:15 time mark for fractions https://youtu.be/pZD5jxgHit0

Subtracting Rational Numbers: a/b-c/b= (a-c)/b

Adding Mixed Numbers: for any rational # a/b, there is a uniquerational # -a/b thats the additive inverse of a/b

EX: in https://docs.google.com/document/d/1qbhIR5Q_Ws4rXuRXJLTzWq08q8LoPNLbibM1dt34TXo/edit?usp=sharing

(a/b)+(-a/b)=0=(-a/b)+(a/b)

+ of Rational #s with unlike denominators

if a/b & c/d are rational numbers then a/b+c/d=(ad+bc)/bd

+ of Rational #s with like denominators

Bar Model using addition- https://docs.google.com/document/d/1RN7_b-bTjvBtb-bxHWyDGNOCM8QcelbD63LZfQX4k_E/edit?usp=sharing

Number Line using addition- https://docs.google.com/document/d/1i_JGxpessqGWUQip_6ibJkOv1kSHjrMRoGFInyQKiNk/edit?usp=sharing

Pie chart using addition-https://docs.google.com/document/d/1OO_pzeMQL_mAVNpSKnfgrNRO7eYN0SqrDKM6_FwHDJw/edit?usp=sharing

If a/b & c/b are rational numbers then a/b+c/b =(a+c)/b