Number Properties Rules Flashcards
Integer divisibility
/ by 3 if
It’s digits add up to a multiple of 3:
516 => 5+1+6=12 => 12/3=4
Integer divisibility
/ By 2 if
The integer is even
Integer divisibility
/ by 4 if
It’s last 2 digits are divisible by 4
54824 => 24/4=6
Integer divisibility
/ by 5 if
It’s last digit is 5 or 0
10, 50, 1050, 28740
Integer divisibility
/ by 6 if
It is a multiple of 2 and 3
558 is even => multiple of 2
5+5+8=18 => 18/3=6 => multiple of 3
Integer divisibility
/ by 8 if
It’s last 3 digits are a multiple of 8
17336 => 336/8=42 => divisible by 8
Integer divisibility
/ by 9 if
Digits add to a multiple of 9
6417 => 6+4+1+7=18
18/9=2 => 6417 is divisible by 9
Integer divisibility
/ by 10 if
It ends in 0
100, 1790, 12460
Integer divisibility
/ by 12 if
Multiple of 3 and 4
Least common multiple
1) Do a factor tree
18=2^13^2
24=2^33^1
LCM=2^33^2=89=72
Do it
Negative exponents
2^-4
X^-1
X^-2
Positive reciprocal
1/2^4=1/16
1/X
1/X^2
Exponent combinations:
X^2Y^3=xxyy*y
n^53^-4=(nnnnn)/(3333)
Do it
Exponent multiplication:
(2^3)(2^2)=
Add the exponents
=(222)(2*2)=2^5
Exponent division with same base
4^9/4^4=
Subtract exponents
4^(9-4)=4^5
(a^6b^3)/(a^2b)=
=(a^6/a^2)(b^3/b)=(a^6-2)(b^3-1)
=a^4*b^2