Understanding Place Value
How does a digit's position determine its value?
๐ Standards & Objectives
- Identify the place value and value of any digit in a whole number
- Identify the place value and value of any digit in a decimal
- Explain how a digit's value changes by ร10 or รท10 when it shifts position
๐ Place Value Is Everywhere!
$1,234.56 โ Each digit has a different job! The 1 is worth $1,000, the 2 is worth $200, the 3 is worth $30, the 4 is worth $4, and the 5 is worth 50 cents!
Spokane has 228,989 people. The first 2 represents 200,000 people, the second 2 represents 20,000 people. Same digit, different position, different value!
Earth is 93,000,000 miles from the Sun. We can understand huge numbers by knowing what each digit represents!
๐ Key Vocabulary
The position of a digit in a number. Examples: ones, tens, hundreds, thousands, millions.
The symbols we use to write numbers: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9. Each digit can be placed in different positions.
What a digit is worth based on its place. The 5 in 500 is worth 500. The 5 in 50 is worth 50.
Groups of three digits separated by commas: ones period, thousands period, millions period, billions period.
โจ The Place Value Chart
Let's see where each digit goes in 784,265,319:
โจ Finding a Digit's Value
Use this formula:
Digit ร Place Value = Value
Example: In 784,265,319, what is the value of the 5?
๐จโ๐ซ I Do: Finding Value (Whole Numbers)
Question: In 784,265,319, what is the value of the 5?
๐จโ๐ซ I Do: Finding Value
Question: In 9,372,645, what is the value of the 3?
๐ฅ We Do: Finding Value
Question: In 284,625,103, what is the value of the 6?
๐ฅ We Do: Finding Value
Question: In 491,528, what is the value of the 4?
โ๏ธ You Do: Finding Value
Question: In 3,816,472, what is the value of the 8?
Work this one on your own! Hint: Find the place value first, then multiply.
โ๏ธ You Do: Finding Value
Question: In 52,937,610, what is the value of the 9?
Work this one on your own! Hint: Find the place value first, then multiply.
โจ Decimal Place Values
Decimals extend the place value chart to the right of the decimal point:
Tenths: 1 รท 10 = 0.1
Hundredths: 1 รท 100 = 0.01
Thousandths: 1 รท 1,000 = 0.001
๐จโ๐ซ I Do: Finding Value (Decimals)
Question: In 265,319.847, what is the value of the 4?
๐จโ๐ซ I Do: Finding Value
Question: In 56,912.734, what is the value of the 7?
๐ฅ We Do: Finding Value
Question: In 2,485.396, what is the value of the 3?
๐ฅ We Do: Finding Value
Question: In 80,622.54, what is the value of the 5?
โ๏ธ You Do: Finding Value
Question: In 63,248.517, what is the value of the 1?
Work this one on your own! Hint: The 1 is in a decimal place.
โ๏ธ You Do: Finding Value
Question: In 7,450.283, what is the value of the 8?
Work this one on your own! Hint: The 8 is in a decimal place.
โจ The ร10 / รท10 Pattern
Look at how digits relate to their neighbors in 522,894.737:
Moving LEFT: Each place is ร10 the place to its right
Example: The 8 (Hundreds = 800) is 10 times the 9 (Tens = 90)
Moving RIGHT: Each place is รท10 the place to its left
Example: The 7 (Tenths = 0.7) is 1/10 of the 4 (Ones = 4)
๐จโ๐ซ I Do: Comparing Place Values
Question: In 56,442.39, compare the two 4s.
๐ฅ We Do: Comparing Place Values
Question: In 23,936.7, compare the two 3s.
โ๏ธ You Do: Comparing Place Values
Question: In 84,571.58, compare the two 5s.
Work this one on your own! Hint: One 5 is in the hundreds place, the other is in the tenths place.
๐ Challenge Round!
Complete each statement. Click to check!
300 is 10 times as much as ___
30
300 is 1/10 as much as ___
3,000
0.4 is 10 times as much as ___
0.04
0.4 is 1/10 as much as ___
4
๐ฌ Turn & Talk
Discuss with a partner:
Question 1: Why is understanding the ร10 / รท10 pattern helpful when working with place value?
Question 2: How is the decimal place value system related to the whole number place value system?
๐ Key Takeaways
๐ซ Exit Ticket
Answer these questions to show what you've learned!
1. In 47,056,918.32, what is the value of the 5?
50,000
The 5 is in the Ten Thousands place: 5 ร 10,000 = 50,000
2. In 8,425.363, what is the value of the 3 in the hundredths place?
0.03
The 3 is in the Hundredths place: 3 ร 0.01 = 0.03
3. The 4 in 65,742.183 = 40. The 4 in 94.506 = 4. 40 is ___ times the value of 4.
10 times
40 รท 4 = 10, so 40 is 10 times as much as 4