Place Value
What is Place Value?
Place value is the value of a digit based on its position in a number. The same digit means different things in different positions.
The number 333 has three 3s โ but each one has a different value: 300, 30, and 3. This is the power of our place value system.
Key Terms
- Digit: one of the symbols 0โ9 used to write numbers
- Place value: the value a digit has because of where it sits in a number
- Expanded form: writing a number as a sum of each digit times its place value
- Standard form: the normal way of writing a number (e.g. 43,265)
The Place Value Chart
| Millions | Hundred-thousands | Ten-thousands | Thousands | Hundreds | Tens | Ones |
|---|---|---|---|---|---|---|
| 1,000,000 | 100,000 | 10,000 | 1,000 | 100 | 10 | 1 |
Each column is 10 times the value of the column to its right.
In the number 3,742:
- 3 is in the thousands place โ value = 3,000
- 7 is in the hundreds place โ value = 700
- 4 is in the tens place โ value = 40
- 2 is in the ones place โ value = 2
Decimal Place Values
Place value extends to the right of the decimal point too:
| Ones | . | Tenths | Hundredths | Thousandths |
|---|---|---|---|---|
| 1 | . | 0.1 | 0.01 | 0.001 |
In 2.049:
- 2 is in the ones place
- 0 is in the tenths place
- 4 is in the hundredths place
- 9 is in the thousandths place
Expanded Form
Writing a number in expanded form shows each digit's value separately:
- 43,265 = 40,000 + 3,000 + 200 + 60 + 5
- 3,506 = 3,000 + 500 + 0 + 6 = 3,000 + 500 + 6
- 2.049 = 2 + 0.04 + 0.009
Notice that zero-value digits can be skipped in expanded form but must be included as placeholders in the standard number.
Worked Example
Write 70,000 + 400 + 8 as a standard number.
- Seventy-thousands column: 7
- Ten-thousands: 0 (placeholder needed)
- Thousands: 0 (placeholder needed)
- Hundreds: 4
- Tens: 0 (placeholder needed)
- Ones: 8
Answer: 70,408
Comparing Numbers
To compare two numbers, line up the digits by place value and look at the highest place first:
47,821 vs 47,912:
- Both have 4 ten-thousands and 7 thousands โ equal so far
- Hundreds: 8 vs 9 โ 9 is greater
- So 47,912 > 47,821
Ordering and the Role of Zero
Zero acts as a placeholder โ without it, 3,042 would look like 342, completely changing its value. Never drop a zero from the middle of a number.
When ordering numbers:
- Count the digits โ more digits means a larger number (in whole numbers)
- If the digit count matches, compare from the leftmost digit
Why Place Value Matters
Place value is the foundation for:
- Reading and writing large numbers accurately
- Comparing and ordering numbers
- Performing addition, subtraction, multiplication, and division correctly
- Understanding decimals and their sizes
- Rounding to various degrees of accuracy
Common Mistakes to Avoid
- Dropping placeholder zeros: 3,042 is NOT the same as 342
- Confusing the digit with its value: In 4,700, the digit 7 has a value of 700, not 7
- Misreading decimal places: 0.3 is three tenths, NOT three hundredths
- Forgetting commas group in threes: 1,000,000 (one million) not 10,00,00
Tips and Tricks
- Use a place value chart when you are unsure โ write each digit in its column
- To multiply by 10, shift every digit one place to the left (do not just "add a zero")
- To divide by 10, shift every digit one place to the right
- When reading large numbers, group digits in threes from the right: 4,327,891
Questions & comments
Comments are public and are checked before they appear. Please donโt post your full name, email, phone number, school, or anything else that identifies you. How we use this.
Loading commentsโฆ