Hierarchy of Decimal Numbers
Number
0
1
2
3
4
5
6
7
8
9
10
20
30
40
50
60
70
80
90
Number
100
1,000
10,000
100,000
1,000,000
Name
zero
one
two
three
four
five
six
seven
eight
nine
ten
twenty
thirty
forty
fifty
sixty
seventy
eighty
ninety
Name
one hundred
one thousand
ten thousand
one hundred thousand
one million
How many
two tens
three tens
four tens
five tens
six tens
seven tens
eight tens
nine tens
How Many
ten tens
ten hundreds
ten thousands
one hundred thousands
one thousand thousands
Some people use a comma to mark every 3 digits. It just keeps track of the digits and makes the
numbers easier to read.
Beyond a million, the names of the numbers differ depending where you live. The places are grouped
by thousands in America and France, by the millions in Great Britain and Germany.
©B.Prazak Gr 8 Math WES
Sunday, April 12, 2020
Hierarchy of Decimal Numbers
Name
million
billion
trillion
quadrillion
quintillion
sextillion
septillion
octillion
googol
googolplex
American-French
English-German
1,000,000
1,000,000
1,000,000,000 (a thousand millions)
1,000,000,000,000 (a million millions)
1 with 12 zeros
1 with 18 zeros
1 with 15 zeros
1 with 24 zeros
1 with 18 zeros
1 with 30 zeros
1 with 21 zeros
1 with 36 zeros
1 with 24 zeros
1 with 42 zeros
1 with 27 zeros
1 with 48 zeros
1 with 100 zeros
1 with a googol of zeros
Fractions Digits to the right of the decimal point represent the fractional part of the decimal number.
Each place value has a value that is one tenth the value to the immediate left of it.
Number
.1
.01
.001
.0001
.00001
Name
tenth
hundredth
thousandth
ten thousandth
hundred thousandth
Examples:
0.234 = 234/1000 (pronounced: two hundred thirty-four thousandths)
4.83 = 4 83/100 (pronounced: 4 and 83 hundredths)
SI Prefixes
Number Prefix Symbol
10 1
deka- da
2
10
hecto- h
3
10
kilo- k
6
10
mega- M
9
10
giga- G
10 12
tera- T
15
10
peta- P
18
10
exa- E
21
10
zeta- Z
24
10
yotta- Y
©B.Prazak Gr 8 Math WES
Number Prefix Symbol
10 -1
deci- d
-2
10
centi- c
-3
10
milli- m
-6
10
micro- u (greek mu)
-9
10
nano- n
10 -12
pico- p
-15
10
femto- f
-18
10
atto- a
-21
10
zepto- z
-24
10
yocto- y
Sunday, April 12, 2020
Fraction
1/10
1/100
1/1000
1/10000
1/100000
Hierarchy of Decimal Numbers
Roman Numerals
I=1
(I with a bar is not used)
V=5
_
V=5,000
X=10
_
X=10,000
L=50
_
L=50,000
C=100
_
C = 100 000
D=500
_
D=500,000
M=1,000
_
M=1,000,000
Examples:
11 = XI
1=I
12 = XII
2 = II
13 = XIII
3 = III
14 = XIV
4 = IV
15 = XV
5=V
16 = XVI
6 = VI
17 = XVII
7 = VII
18 = XVIII
8 = VIII
19 = XIX
9 = IX
20 = XX
10 = X
21 = XXI
25 = XXV
30 = XXX
40 = XL
49 = XLIX
50 = L
51 = LI
60 = LX
70 = LXX
80 = LXXX
90 = XC
99 = XCIX
There is no zero in the Roman numeral system.
The numbers are built starting from the largest number on the left, and adding smaller numbers to the
right. All the numerals are then added together.
©B.Prazak Gr 8 Math WES
Sunday, April 12, 2020
Hierarchy of Decimal Numbers
The exception is the subtracted numerals, if a numeral is before a larger numeral; you subtract the
first numeral from the second. That is, IX is 10 – 1 = 9.
This only works for one small numeral before one larger numeral - for example, IIX is not 8, it is not a
recognized roman numeral.
There is no place value in this system - the number III is 3, not 111.
Number Base Systems
Decimal(10)
Binary(2)
Ternary(3)
Octal(8)
Hexadecimal(16)
0
0
0
0
0
1
1
1
1
1
2
10
2
2
2
3
11
10
3
3
4
100
11
4
4
5
101
12
5
5
6
110
20
6
6
7
111
21
7
7
8
1000
22
10
8
9
1001
100
11
9
10
1010
101
12
A
11
1011
102
13
B
12
1100
110
14
C
13
1101
111
15
D
14
1110
112
16
E
15
1111
120
17
F
16
10000
121
20
10
17
10001
122
21
11
18
10010
200
22
12
19
10011
201
23
13
20
10100
202
24
14
Each digit can only count up to the value of one less than the base. In hexadecimal, the letters A - F
are used to represent the digits 10 - 15, so they would only use one character.
©B.Prazak Gr 8 Math WES
Sunday, April 12, 2020