Page 11 - ICSE Math 4

Number
1 Numberss

Learning Outcomes

Students will be able to learn:
 about large numbers (up to lakh).
 to write place value and face value.
 how to arrange numbers in ascending and descending order.
 how to form of the largest and the smallest numbers from the given digits.

Number System

We follow two types of number systems to read and write large numbers. One is the
Indian number system which is followed in India and the other one is the Interna onal
number system which is followed worldwide.
Let’s learn both the number systems.

Indian Number System

To write the number names of large numbers, we divide them into groups. Each group is
called a period. Let’s consider the number 137546.

• Start from extreme right and make a group of three digits. 137546
This is the fi rst group which consists of ones, tens and hundreds. It is called the ones

period.
• The second group consists of the next two digits, i.e., thousands and ten thousands.
It is called the thousands period. 137 546

• Now only one digit is le . It will come in the next period which is called the lakhs
period. 1 37 546

In a number, any two periods are grouped and separated by pu ng commas. Thus,
137546 is wri en as 1,37,546 and is read as one lakh thirty-seven thousand fi ve
hundred forty-six.

Periods  Lakhs L Thousands (Th) Ones (O)

Place Value Ten Lakhs Ten Thousands Hundreds Tens Ones
Lakhs (L) Thousands (Th) (H) (T) (O)

(TL) (TTh)
1,37,546 1 3 7 5 4 6

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