PLACE VALUE OF WHOLE NUMBERS AND DECIMAL

Back to: Mathematics Primary 5

HELLO, WELCOME BACK TO CLASS

 

What is place value?

Place value is the value given to a digit by its position in a number

The position or place of a digit in a number written in standard form determines the actual value the digit represents. For example, in the number 482, the value of the digit ‘4’ is 400, the value of the digit ‘8’ is 80 and the value of the digit ‘2’ is simply 2. A digit is any of the symbols used to write numbers 0, 1, 2, 3, 4, 5, 6, 7, 8, 9. A place-value chart shows the value of the digits in a number. Each group of the three digits is called a period. Each period is separated by a comma.

PLACE VALUE THROUGH MILLIONS

 

PLACE VALUE THROUGH MILLIONS

 

• Ones

10                                                                    Tens

100                                                                 Hundreds

1,000                                                              Thousands

10,000                                                            Ten Thousands

100,000                                                          Hundred Thousands

1,000,000                                                      Millions

CONSIDER THIS NUMBER

4,328,765

You can use a place-value chart to show the value of its digits:

Millions	Hundred Thousands	Ten Thousands	Thousands	Hundreds	Tens	Ones
4,	3	2	8,	7	6	5

If someone asks you the value of a particular digit of this number, you can use the chart to find the answer. For example, what is the value of the digit 8 in the number 4,328,765? The digit 8 is in the thousands column, or the fourth column from the right; therefore, it means 8 thousands.

Using this chart, you can also rename the entire number to show the place value of each digit, as follows:

4,328,765 = 4 millions + 3 hundred thousands + 2 ten thousands + 8 thousands + 7 hundreds + 6 tens + 5 ones

 

IDENTIFY VALUES OF DIGIT

EXAMPLE 1:

Write the place value of the underlined digit in 283,420.

Step 1: Identify the underlined number

3

Step 2: Replace all the digits after the underlined number with zeros

 

The underlined digit has a value of 3,000

The Place Value is 3 Thousands

 

EXAMPLE 2:

Find the value of the underlined digit in 4,250,021.

Step 1: Identify the underlined number

4,250,021

4,

Step 2: Replace all the digits after the underlined number with zeros                                                                          4,250,021

4,000,000

The value is 4,000,000

The place value is 4 Millions

 

In expanded form it becomes:

600.000,000 + 50,000,000 + 7,000,000 + 300,000 + 40,000 + 5,000 + 900 +7

In words, it is: Six hundred and fifty-seven million, three hundred and forty-five thousand, nine hundred and seven.

A number in standard form is separated into groups of three digits using commas. Each of these groups is called a PERIOD.

Note: one billion has 10 digits and 9 zeros:1,000,000,000

One million has 7 digits and 6 zeros:1,000,000

One Trillion = 1,000,000,000,000

One Quadrillion = 1,000,000,000,000,000

DECIMAL PLACE VALUE

Note: the first place value after the point always stand for tenth

e.g.            

e.g.               

WRITING IN WORDS AND FIGURES

0.216     –  Zero point two one six

146.419 –  One hundred and forty six point four one nine

431.578 –  Four hundred and thirty one point five seven eight

Quiz

1. a) What is the value of the digit that is underlined?

• 4567
• 34289
• 457329
• 1657389
• 3246781

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