ISEE Upper Level Math : ISEE Upper Level (grades 9-12) Mathematics Achievement
Study concepts, example questions & explanations for ISEE Upper Level Math
All ISEE Upper Level Math Resources
Example Questions
Example Question #2 : How To Find Out If A Number Is Prime
How many composite numbers are between and
inclusive?
There are twenty integers from to
inclusive. Counting composite numbers can be made easier by weeding out the primes -
. Removal of these five primes leaves
Example Question #7 : Prime Numbers
Which of the following numbers is prime?
The correct answer to this question is 
Next, determine if the number is divisible by any prime numbers up to and including the square root. In this instance consider the numbers:
Example Question #4 : How To Find Out If A Number Is Prime
How many composite numbers are between 
There are thirty integers from 
Example Question #3 : How To Find Out If A Number Is Prime
Reduce the fraction:
First, given that 13 times 4 is 52, the numerator can be simplified by taking the square root of 4 and multiplying it by the square root of 13.
Example Question #6 : How To Find Out If A Number Is Prime
How many prime numbers are there between 1 and 20?
11
9
2
8
7
8
A prime number is one in which only itself and 1 can go into it. Therefore, 2, 3, 5, 7, 11, 13, 17, and 19 are the only prime numbers in that set.
Example Question #471 : Isee Upper Level (Grades 9 12) Mathematics Achievement
Which of the following is a prime number?
Which of the following is a prime number?
The answer here is 13, because 13 has no factors other than 1 and itself.
51 is divisible by 3 and 17.
39 is divisible by 13 and 3.
81 is divisible by 9, 3, and 27
Example Question #32 : Numbers And Operations
Find the sum of all the prime numbers between 
The prime numbers between 
Example Question #472 : Isee Upper Level (Grades 9 12) Mathematics Achievement
30 is the least common mutiple of 10 and which of these numbers?
9, 12, and 20 can be eliminated immediately, since none of these have 30 as a multiple [30 divided by any of them yields a remainder].
The set of multiples of 10 is 
Example Question #473 : Isee Upper Level (Grades 9 12) Mathematics Achievement
What is the least common multiple of 16 and 20?
The multiples of 16:
The multiples of 20:
Example Question #474 : Isee Upper Level (Grades 9 12) Mathematics Achievement
Which of the following is the least common multiple of 6, 9, and 12?
36
12
648
18
36
The least common multiple is the smallest number in value that is a multiple of all three of the numbers. The best way to find the least common multiple (LCM) is to make a quick list of the first few multiples of each number, and then identify the smallest number that is common to all three lists.
Multiples are numbers that you get when multiplying the original number by other numbers.
18 is an answer choice that is common to both 6 and 9, but it is not also a multiple of 12, so it is not correct.
The smallest value that is a common multiple of all three is 36, so this is the LCM.
While 648 is a multiple of all three numbers, it is not the least common multiple of the three numbers.
All ISEE Upper Level Math Resources
