Place value tells you how much each digit stands for
Use a hyphen when you use words to write 2-digit numbers greater than 20 that have a digit other than zero in the ones place.
Example: Write 57 in words.
Example: Write 80 in words.
A place-value chart tells you how many hundreds, tens, and ones to Use.
Example: A supermarket has 258 boxes of cereal on its shelves.
|Number||Place Value||Value of digit|
|1,23 4||Units / Ones||4|
|7,8 91,234||Ten thousands||90,000|
|567, 891,234||Hundred thousands||800,000|
|5 67,891,234||Ten millions||60,000,000|
Zeros may stand for nothing, but that doesn’t mean you can leave them out. They keep other digits in the correct places.
Think: 2 thousand + 0 hundred + 4 tens + 0 ones
Say: Two thousand Forty
Place Value Through The Millions
|Millions Period||Thousands Period||Ones Period|
The digits in large numbers are in groups of three places. The groups are called periods.
Commas are usually used to separate the periods
Example: What is the value of the digit 4 in 71,502,600?
Answer: The digit 4 is in the hundred thousands place. Its value is 5 hundred thousand or 500,000.
International Place Value System
Example 9 – Write the number 27349811 in the International place value system. Also write it with commas and in words.
With commas – 27,349,811
In words – Twenty seven million three hundred forty nine thousand eight hundred eleven.
COMPARE THE TWO SYSTEMS
In both the systems 5-digit numbers are read in the same way.
INDIAN SYSTEM INTERNATIONAL SYSTEM
6-digit numbers 1 lakh = 100 thousand
7-digit numbers 10 lakhs = 1 million
8-digit numbers 1 crore = 10 million
9-digit numbers 10 crores = 100 million
Example-10 In the number 783425, write the digit that is in –
(a) hundreds place (b) hundred thousands place
© ten thousands place (d) Ones place
Sol. Ans. (a) 4 (b) 7 (c) 8 (d) 5.
Finding value of a digit in a Number
A digit’s value in a number = (Face value of the digit) × (Place value of the digit)
So, for any two digit number ab, the place value of b is 1 and that of a is 10 and it can be represented as:
ab = (a × 10)+(b × 1)
So, with the help of variables a and b any two digit number can be represented in the form given above.
Variables a and b can take any value from 0 – 9 as they represent the face value of digits.
Similarly, a three digit number abc can be represented using its place value as:
abc = (a × 100) + (b × 10) + (c × 1)
In this case also, a,b and c are single digit variables as they represent face value of digit, can take any value from whole numbers 0-9 and can represent any three digit number.
Consider the positions of variables a,b,c are swapped for b,a,c then using the above rule, it can be expressed as:
bac = (b × 100) + (a × 10) + (c × 1)