GMAT數學輔導：算術知識點全解析
GMAT數學輔導：算術知識點全解析
一.整數：integer，whole number 因子：factor or divisor
If x and y are integers and x0,x is a divisor of y provided that y=xn for some integer n. In this case y is also said to be divisible by x or to be a multiple of x. For example, 7 is a divisor or factor of 28 since 28=74, but 8 is not a divisor of 28 since there is no integer n such that 28=8n.Divisible adj.可以被整除的 multiple n.倍數
2.商和余數：quotients and remainders
余數和商都可以為0
3.奇數和偶數：odd and even integers
奇數和偶數都可以是負數;零一定是偶數
4.質數和合數：prime numbers and composite numbers
A prime number is a positive integer that has exactly two different positive divisors，1 and itself. For example, 2,3,5,7,11, and 13 are prime numbers, but 15 is not, since 15 has four different positive divisors, 1, 3, 5, and 15. The number 1 is not a prime number, since it has only one positive divisor. Every integer greater than 1 is either prime or can be uniquely expressed as a product of prime factors. For example, 14= , 81= , and 484= .
注:除了1和其本身外,還有其他因子的數叫合數。最小的質數為2，最小的合數為4，在討論質數和合數時，都指正數。1和0既不是質數，也不是合數。
GMAT數學輔導：算術知識點全解析
一.整數：integer，whole number 因子：factor or divisor
If x and y are integers and x0,x is a divisor of y provided that y=xn for some integer n. In this case y is also said to be divisible by x or to be a multiple of x. For example, 7 is a divisor or factor of 28 since 28=74, but 8 is not a divisor of 28 since there is no integer n such that 28=8n.Divisible adj.可以被整除的 multiple n.倍數
2.商和余數：quotients and remainders
余數和商都可以為0
3.奇數和偶數：odd and even integers
奇數和偶數都可以是負數;零一定是偶數
4.質數和合數：prime numbers and composite numbers
A prime number is a positive integer that has exactly two different positive divisors，1 and itself. For example, 2,3,5,7,11, and 13 are prime numbers, but 15 is not, since 15 has four different positive divisors, 1, 3, 5, and 15. The number 1 is not a prime number, since it has only one positive divisor. Every integer greater than 1 is either prime or can be uniquely expressed as a product of prime factors. For example, 14= , 81= , and 484= .
注:除了1和其本身外,還有其他因子的數叫合數。最小的質數為2，最小的合數為4，在討論質數和合數時，都指正數。1和0既不是質數，也不是合數。
