# Numbers Our friends

Learning Objective
Place value(Indian and International system of
numeration)
Comparison of numbers( Ascending and Descending
Order)
Roman numbers
PLACE VALUE
O Place value of a digit in a given number is
the value of the digit because of the place or
the position of the digit in the number.
O They are two types:
O Indian System
O International System
Indian System
O In the Indian system of numeration, starting
from the right, the first period is the ones
period consisting of three place- ones, tens
and hundreds. The other periods to the left
of the ones period have two places values
each.
INTERNATIONAL SYSTEM
O In the International System of
numeration, all the periods have
three place values each.
COMPARISON OF NUMBERS
O They are two types :
O Ascending and Descending Order.
Ascending Order
O Arrangement of the numbers from smallest to largest
is called ascending order.
O Eg :
O
15,40,532 4,24,572 3,13,01,046 74,058
O ans :74,058
4,24,572 15,40,532 3,13,01,406
Descending Order
O Arrangement of numbers from largest to smallest is
called descending order.
O Eg : 35,40,872 35,27,840 87,20,354 2,78,345
O Ans ; 87,20,354 35,40,872 35,27,840 2,78,345
There are four basic principles for reading
Roman
Numerals
and writing Roman numerals:
• 1 A letter repeats its value that many
times (XXX = 30, CC = 200, etc.). A
letter can only be repeated three times.
• 2 If one or more letters are placed after
another letter of greater value, add that
amount.VI = 6 (5 + 1 = 6)LXX = 70 (50 + 10
+ 10 = 70)MCC = 1200 (1000 + 100 + 100
= 1200)
O 3. If a letter is placed before another
letter of greater value, subtract that
amount. IV = 4 (5 – 1 = 4)XC = 90 (100 –
10 = 90)CM = 900 (1000 – 100 = 900)
Several rules apply for subtracting
amounts from Roman numerals:
O a. Only subtract powers of ten (I, X, or C,
but not V or L)For 95, do NOT write VC
(100 – 5).
DO write XCV (XC + V or 90 + 5)
O b. Only subtract one number from
another. For 13, do NOT write IIXV (15 –
1 - 1).
DO write XIII (X + I + I + I or 10 + 3)
O c. Do not subtract a number from one
that is more than 10 times greater (that
is, you can subtract 1 from 10 [IX] but
not 1 from 20—there is no such number
as IXX.)For 99, do NOT write IC (C – I or
100 - 1).
DO write XCIX (XC + IX or 90 + 9)
O 4. A bar placed on top of a
letter or string of letters
increases the numeral's value
by 1,000 times. XV = 15, =
15,000
One
I
Eleven
XI
Thirty
XXX
Two
II
Twelve
XII
Forty
XL
Three
III
Thirteen
XIII
Fifty
L
Four
IV
Fourteen
XIV
Sixty
LX
Five
V
Fifteen
XV
Seventy
LXX
Six
VI
Sixteen
XVI
Eighty
LXXX
Seven
VII
Seventeen XVII
Ninety
XC
Eight
VIII
Eighteen
XVIII
One
hundred
C
Nine
IX
Nineteen
XIX
Five
hundred
D
Ten
X
Twenty
XX
One
thousand
M
QUESTION TIME
O Write down the place value of a colored
digits:
Qa. 3567956
a. 2030
b. 7000
c. 700000
Qb. 4567889
a. 40000000
b. 4000000
c.
40000007
Q3 . 5678909 write in indian system.
O Fifty six lakh seventy eight thousand nine
hundred eight
O Five hundred sixty nine thousand four lakh
crore.
O Fifty six lakh seventy eight thousand nine
hundred nine..
O Write in roman number.
Q1. 234
a. CCXXXVI
b. CCXXXIV
c. CIVXX
O Write in Hindu-Arabic.
DCC
a. 5200
b. 700
c.
400