Numbers and the number system

Question 1

Prove that 0.222… = 2/9

Answer 1

x = 0.222…
10x = 2.222…
9x = 2

Question 2

x^a*x^b

Answer 2

x^a+b

Question 3

x^a/x^b

Answer 3

x^a-b

Question 4

(x^a)^b

Answer 4

x^a*b

Question 5

(a/b)ⁿ

Answer 5

aⁿ/bⁿ

Question 6

aⁿ*bⁿ

Answer 6

(a*b)ⁿ

Question 7

a^nm

Answer 7

a^(nm)

Question 8

Set

Answer 8

Collection of elements

Question 9

∪

Answer 9

Union - all the elements in A or B or both

Question 10

∩

Answer 10

Intersection - the elements in A and B

Question 11

∈

Answer 11

Is a member

Question 12

∉

Answer 12

Is not a member

Question 13

A^I

Answer 13

Everything not in A

Question 14

Ø

Answer 14

Empty set

Question 15

⊂

Answer 15

Is a subset

Question 16

n(A)

Answer 16

Number of elements in A

Question 17

What is the formula for compound interest?

Answer 17

Original*Interest^{Number of time periods} = New

Question 18

What is the order of place value?

Answer 18

• Ten thousands
• Thousands
• Hundreds
• Tens
• Units
• Tenths
• Hundredths
• Thousandths
• Ten thousandths

Question 19

What is the order of operations?

Answer 19

Brackets
Indices
Division
Multiplication
Addition
Subtraction

Question 20

How to find the UB and LB of 24800 to the nearest 100?

Answer 20

1. Divide degree of accuracy by 2 100/2 = 50
2. Add this for UB 24800+50 = 24850
3. Subtract this for LB 24800-50 = 24750

Question 21

UB of a + b

Answer 21

U + U

Question 22

UB of a - b

Answer 22

U - L

Question 23

UB of a*b

Answer 23

U*U

Question 24

UB of a/b

Answer 24

U/L

Question 25

LB of a + b

Answer 25

L + L

Question 26

LB of a - b

Answer 26

L - U

Question 27

LB of a*b

Answer 27

L*L

Question 28

LB of a/b

Answer 28

L/U