Final Exam Flashcards
Divisibility rule of 2
any whole number that ends in 2, 4, 6, 7
rule for 3
sums of the digits is divisible by 3
rule for 4
if the last TWO digits of a whole number are divisible by 4
rule for 5
a whole number that must end in a 5 or 0
rule for 6
for a number to be divisible by 6, it must be divisible by 2 and 3
rule for 7
-take last digit of the number and double it & then subtract that number from the rest until the number is 0 or divisible by 7
rule for 8
if the last THREE digits of a number are divisible by 8
rule for 9
see if the sum of the digits is divisible by 9
rule for 10
- even and divisible by 5
- last number must be a 0
factor
a number that when multiplied with another produces a given number
divisor
the number that you divide by
multiple
a number that can be divided by another number without a remainder
sums of consecutive numbers generalization
- powers of 2 can’t be expressed as a sum of consecutive numbers
- it would result in an odd number
- Example: 2^0 = 1, 2^1=2, 2^2 = 4, 2^3=8 these numbers are not consecutive
- Example: 4^0= 1, 4^1 =4, 4^2 = 16 not consecutive numbers
locker room problem
-lockers that remained open were the square numbers bc they have an odd number of factors (10 remained open)