Grade 8 Math- Fractions

STUDY
PLAY

Terms in this set (...)

Factor
numbers that divide equally into a given number
Multiple
The product of any two numbers that are not zero is a multiple of those numbers
3x7= 21 so 21 is a multiple of 3 and 7
Prime
A number bigger than one that has only two factors: 1 and itself
Composite
A number that has 3 or more factors
Prime Factorization
Breaking down numbers and rewriting it as a product of prime factors
Fraction
Part of a whole
Equivalent Fractions
Fractions that equal the same thing
1/2= 2/4
Simplest Form
The numerator and denominator cannot be reduced anymore by a common factor
Mixed Number
A mix between fractions and a whole number
Improper Fraction
Numerator is greater than the denominator
Cross Reducing
Finding commons factors between one numbers numerator and the other numbers denominator to reduce before multiplying
Reciprocal
The inverse of a fraction
knowledge
doodoodoo
How to find the GCF using the listing method or the prime factors method
Listing:
List the factors until you find a common one.

18: 1, 2, 3, 6, 9, 18
24: 1, 2, 3, 4, 6, 8, 12, 24
GCF= 6

Prime factors:
Find the prime factorization of each.Circle the common digits between the two. Multiply the common digits and that is your GCF

36: 2x2x3x3
42: 2x3x7
2x3=6
GCF=6
How to find the LCM of numbers using the listing method or the prime factors method
Listing:
List until you find common multiples
2: 2, 4, 6, 8, 10, 12
3: 3, 6, 9, 12
4: 4, 8, 12


Prime factorization:
Figure out the prime factorization of each. Cross out common digits. Multiply the remaining numbers of the smaller digit times the bigger number out of the two.

Ex:
8: 2x2x2
14: 7x2
LCM= 2x2x14= 56
=56
How to reduce fractions to simplest form
Find common factors between the numerator and denominator then divide by that factor.
6/102 ➗ 2
= 3/51 ➗ 3
= 1/17
How to create equivalent fractions
Multiply or divide the numerator and denominator by the same common factor
1/2 x 7= 7/14
1/2= 7/14
8/12➗ 4= 2/3
8/12= 2/3
How to convert from mixed number to improper fraction
take the mixed number multiply it by the denominator and add the product to your numerator
ex: 4 6/8
= 4x8
=32+6
=38/8
How to order fractions
Change all of the denominators to the same one. Order. Change back to it's original form. Include greater than/ less than signs in your final answer
How to add and subtract fractions and mixed numbers with unlike denominators
change all mixed numbers to improper fractions. Make sure they all have the same denominator. Add or subtract. Put in simplest form
How to multiply fractions and mixed numbers using cross reducing
Change all mixed numbers to improper fractions. Cross reduce. Multiply. You shouldn't have to simplify but if needed do it .
How to divide fractions and mixed numbers using a reciprocal
Change all mixed numbers into improper fractions. Reciprocate all fractions aside from the first one. Multiply and cross reduce if needed
How to use exponents and square roots with fractions
Exponents: To determine the base you have to solve a couple simple rules. If the question is in brackets to have to increase both the numerator and the denominator. If the exponent is on either the numerator or the denominator you only increase the one it's on. Once you determine the base you solve like any other power and simplify

Square roots. If the entire question is under a square root symbol you have to square root both the numerator and the denominator. If the square root symbol is on either the numerator or the denominator you only square root the one it's on. Once you determine what your square rooting you solve like any other problem and simplify
How to convert a fraction to a decimal
Figure out if it's out of .1 .01 or .001. Then convert.
ex: 87/100= 0.87
50/100= 0.5
The pattern of fractions with denominator's of 9 or 8
8: increase by .125 each time
9: repeat numerator ex: .555555555555555555555 etc.
How to tell if a fraction will terminate, repeat or be mixed using the prime factorization
Terminating: denominators only prime factors are 2 or 5 ex: 1/4(x25)= 0.25
Repeat: None of the denominators prime factors are 2 or 5
ex: 1/11= 0.09090909090909090909090909090909......
Mixed: One prime factor is 2 or 5 and then another one
1/6= 0.1666666666666666666666666.....