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23 Cards in this Set
 Front
 Back
even+even=

even


odd+odd=

even


even+odd=

odd


even*even=

even


odd*odd=

odd


even*odd=

even


Prime Numbers up to 30

2,3,5,7,11,13,17,19,23,29
1 Is not a prime number 2 Is the only even prime number 

Divisibility
A number is divisible by 2 if.. 
its units digit is divisible by 2
10,592 is divisible by 2 because its units digit (2) is even. 

Divisibility
An integer is divisible by 3 if... 
the sume of its digits is divisible by 3.
2,145 is divisible by 3 because 2+1+4+5=12 and 12/3 is 4 no remainder. 

Divisibility
An integer is divisible by 4 if... 
its last two digits form a number thats divisible by 4.
94,203,012 is divisible by 4 because its last two digits (12) is divisible by 4. 

Divsibility
An integer is divisible by 5 if... 
its units digit is either 0 or 5.


Divisibility
An integer is divisible by 6 if.... 
its divisible by both 2 and 3.
Remember its divisible by 2 if its last digit is even. So numbers ending in 1,3,5,7,9 can not be divisible by 6. To be divisible by 3, its its digits must add up to a number divisible by 3. 99936 is divisible by 6 because 6 is even and 9+9+9+3+6= 36 which is divisible by 6. 

Divisibility
An integer is divisible by 9 if 
the sum of its digits is divisible by 9.
90045 is divisible by 9 because 9+0+0+4+5=18 which is divisible by 9. 

Formula for percentage increase/decrease?

Percentage change = ((difference between new and original)/original )* 100


(x^a)(y^a)

(xy)^a


Common Root
√1 
1


Common Root
√2 
1.4


Common Root
√3 
1.7


Common Root
√4 
2


Factored
x^2y^2 
Unfactored
(x+y)(xy) 

Factored
(x+y)^2 
Unfactored
x^2+2xy+y^2 

Factored
(xy)^2 
Unfactored
X^22xy+y^2 

Common Pathogorean Triangles

345
6810 51213 Or some multiple of them 