Math Accuplacer

### divisible by 3

if the sum of the digits is divisible by 3

Ex) 456 ---> 4+5+6=15, 15 is divisible by 3

### divisible by 4

if the number named by the last 2 digits is divisible by 4

Ex) 3936 is divisible by 4 because 36 is divisible by 4

### divisible by 6

if rules for 2 and 3 check out ---- 1) the number is even & 2) the sum of the digits is divisible by 3

### divisible by 8

if the number named by the last three digits is divisible by 8

Ex) 13802120 ---> 120/8 = 15

### divisible by 9

if the sum of the digits is divisible by 9

Ex) 3483 ---> 3+4+8+3=18, 18 is divisible by 9

### divisible by 11

if the difference between the sum of the even-place digits and the sum of the odd-place digits is a multiple of 11

Ex) 928,193,926 ---> odd sum (9+8+9+9+6=41) even sum (2+1+3+2=8) ---> 41-8=33, 33 is divisible by 11

### multiplying decimals

count the number of decimal places and add them

Ex) 45.67 x .987 (5 places) = 45.07629 (5 places)

### dividing decimals

move the decimal point in the divisor and the dividend the same number of places to get whole numbers

Ex) 23.1 / .004 ----> 23.1 x 1000 / .004 x 1000 ----> 23100/4 ---> 5775