Test 2 Review

Factors & Multiples

100

List the first six multiples of 8. 

0, 8, 16, 24, 32, 40

200

List all factors of 54.

1, 2, 3, 6, 9, 18, 27, 54

300

Test 543,101,892 for divisibility by 2, 3, 4, 5, 6, 9 and 10. 

Yes: 2, 3, 4, 6

No: 5, 9, 10

400

Find the prime factorization of 1617.

1617 = 3 x 7² x 11

500

If a number has an odd number of factors, then it is...

A perfect square!

Squares & Square Roots

100

What is the square root of 196?

14

200

What is the square root of 879,546,312²?

879,546,312

300

What is the square root of 12,100,000,000?

110,000

400

What is the square root of 576?

24

500

Translate to math and evaluate: "The product of eighty-one and the square root of the difference of one hundred and nineteen".

Write on board -> 729

Primes & Composites

100

Is 2 prime or composite? 

2 is prime! Only factors are 1, 2. 

200

Is 1 prime or composite? 

1 is neither prime nor composite! It has exactly one factor. 

300

Is 123,456,789 prime or composite? 

Composite! For example, 3 is a factor. 

400

Is 181 prime or composite? 

Prime! Need to test 2, 3, 5, 7, 11, 13

500

True or False? If a number fails the divisibility tests for 2, 3, 4, 5, 6, 9, and 10, then it is prime. 

False! e.g. 49

GCF & LCM

100

GCF(18,45) = ?

LCM(18,45) = ?

GCF(18,45) = 9

LCM(18,45) = 90

200

GCF(8, 48, 108) = ?

LCM(8, 48, 108) = ?

GCF(8, 48, 108) = 4

LCM(8, 48, 108) = 432

300

Beginning at 8:30 A.M., tours of the National Capitol and the White House begin at a tour agency. Tours for the National Capitol leave every 35 minutes. Tours for the White House leave every 20 minutes. What is the first time after 8:30 that the tours will leave at the same time?

LCM(20, 35) = 140, so the tours leave together every 140 minutes. The first time 140 mins after 8:30 -- 10:50 AM. 

400

If a is a factor of b, GCF(a,b) = ? LCM(a,b) = ?

GCF(a,b) = a

LCM(a,b) = b

500

If a and b are relatively prime, GCF(a,b) = ? LCM(a,b) = ?

GCF(a,b) = 1

LCM(a,b) = ab

Fractions

100

What is the quotient of four hundred thirty-nine and six hundred eighty-three?

439/683

200

Fill in the blank:

3 x _____ = 57/101

3 x 19/101 = 57/101

300

Express 88/143 in lowest terms.

8/13

400

True or false? If a fraction is in lowest terms, then either its numerator or denominator must be prime. 

False, e.g. 25/36

500

Write a fraction that is equivalent to 17/153 and has denominator 81. 

17/153 -> 1/9 -> 9/81