The Number System Review

GCF, LCM

100

What is the LCM (least common multiple) of 6 and 4?

Answer: 12

Multiples of 6: 6,12,18,24

Multiples of 4: 4,8,12,16,20 --> 12 shows up first on both lists.

200

What is the GCF (greatest common factor) of 16 and 48? 

Answer: 16

Factors of 16: 1,2,4,8,16

Factors of 48: 1,2,3,4,6,8,12,16,24,48

16 is the largest number that is shown on the list.

300

What is the least common multiple of 9 and 12? 

Answer: 36

Multiples of 9: 9,18,27,36

Multiples of 12: 12,24,36

36 shows on the list first!

400

What is the greatest common factor of 54 and 32? 

GCF: 2

Factors of 32: 1,2,4,8,16,32

Factors of 54:1,2,3,6,9,18,27,54

2 is the greatest number that shows up in both lists

500

Explain in your own words:

How do I find the GCF of two numbers? 

AND

 How do I find LCM of two numbers?

Answer: 

GCF can be found by listing the factors of each number and finding the greatest number that shows up in both lists.

LCM can be found by listing the multiples of each number and finding the number that shows up first in both lists.

Division =)

100

Evalue the following division facts

12 / 3 =

36/6 = 

48/6 = 

Answers: 4,6,8 

12 / 3 = 4

36/6 = 6

48/6 = 8

200

Evaluate:

26 divided by 8? 

Answer: 3.25 

3.25 x 8 = 26

300

Divide:  3.48/1.5

Answer: 2.32

1.5 x 2.32 = 3.48

400

Evaluate:

156 / 25 

Answer:6.24

6.24 x 25 = 156

500

Divide: 

43.488 /1.2 = 

Answer: 36.24

Change divisor by moving the decimal: 

434.88/12 = 36.24

Working with Signs

100

What is the opposite of 4?

Answer: -4 

Opposites have opposite signs (+/-)

200

What is the absolute value of -3.5 or 

l -3l ?

Answer: 3.5 

Absolute value is the distance away from zero an integer is 

300

What is the value of the expression: (-2)(5)(-3)?  

Answer: 30 

-2 x 5 = -10

-10 x -3 = + 30

400

Which of the three numbers have the greatest absolute value?

A. -15

B. -9

C.  10

Answer: A 

Absolute value of -15 is 15!

Absolute value of -9 is 9.

Absolute value of 10 is 10.

500

Multiply the following values together: 

(The opposite of 7) x (The absolute value of -6)  x - 1 

Answer: 42

opposite of 7 = -7 

Absolute value of -6 = 6

-7 x 6 = -42 x -1 = 42!

Order from least to greatest

100

Order these numbers from least to greatest: 

0,-3,6,-1

Answer: -3, -1,0,6

The larger a negative number, the more negative it is.

200

Order from least to greatest: 

1/2, -1/4, -1/2, 1/3 

Answer:  -1/2, -1/4, 1/3, 1/2 

300

Order from Least to Greatest: 

-2.25, 0, .25, 1.5, -2 1/2, -1/4

Answer: 

-2 1/2, -2.25, -1/4, 0, .25, 1.5 

400

Order from Least to Greatest: 

1/8, -1/2, .5, 2.75, - 4/5, 0 

Answer: -4/5, -1/2, 0, 1/8, .5, 2.75

500

Order from Least to Greatest:

-3, 2 1/4, -3.25, 2.5,- 3 2/3, 2 3/4

Answer: 

-3 2/3, -3.25, -3,  2 1/4,  2.5,  2 3/4 

PEMDAS

100

What does the E mean in PEMDAS?

Answer: Exponents!

x^{2 --> EXPONENT}

200

Evaluate: 

(2+4)²  - 1 

Answer: 35

P: 2+4 = 6

E: 6² = 36

S: 36 -1 = 35

300

Evaluate: 

[16 - (4-2)²  ] + 6(2) 

Answer: 24

P: [16 - (4-2)² ] = 12

M: 6 x 2 = 12

A: 12 + 12 = 24

400

Evaluate: 

(10² / 4 + 5) - 3³ + 8

Answer: 11

P : (10² / 4 + 5) = 100/4 = 25 + 5 = 30

E: 3³ = 27 

S: 30 - 27 = 3

A: 3 + 8 = 11

500

Evaluate: 

(2.3 + 2³ - 5) + 7(2.5+1.5) - 6

Answer: 27.3

P: (2.3 + 2³ -5) = 2³ = 8 +2.3 = 10.3 -5 = 5.3

(2.5+ 1.5) = 4 

M: 7(4) =28

A: 5.3 + 28 =33.3 

S: 33.3 - 6 = 27.3