Expanded Form: Writing a number as the sum of its place values (e.g., 28 = 20 + 8)
- Identify the tens digit and multiply by 10
- Identify the ones digit
- Write as a sum of tens and ones
- Verify by adding to get original number
In 28, the tens digit is 2
2 tens = 2 × 10 = 20
In 28, the ones digit is 8
8 ones = 8
28 = 20 + 8
20 + 8 = 28 ✓
28 = 20 + 8
• Place Value: Tens digit × 10 = tens value
• Expanded Form: Number = tens + ones
• Verification: Adding parts gives original number
In 53, the tens digit is 5
5 tens = 5 × 10 = 50
In 53, the ones digit is 3
3 ones = 3
53 = 50 + 3
50 + 3 = 53 ✓
53 = 50 + 3
• Place Value: Tens digit × 10 = tens value
• Expanded Form: Number = tens + ones
• Verification: Adding parts gives original number
In 74, the tens digit is 7
7 tens = 7 × 10 = 70
In 74, the ones digit is 4
4 ones = 4
74 = 70 + 4
70 + 4 = 74 ✓
74 = 70 + 4
• Place Value: Tens digit × 10 = tens value
• Expanded Form: Number = tens + ones
• Verification: Adding parts gives original number
In 89, the tens digit is 8
8 tens = 8 × 10 = 80
In 89, the ones digit is 9
9 ones = 9
89 = 80 + 9
80 + 9 = 89 ✓
89 = 80 + 9
• Place Value: Tens digit × 10 = tens value
• Expanded Form: Number = tens + ones
• Verification: Adding parts gives original number
In 96, the tens digit is 9
9 tens = 9 × 10 = 90
In 96, the ones digit is 6
6 ones = 6
96 = 90 + 6
90 + 6 = 96 ✓
96 = 90 + 6
• Place Value: Tens digit × 10 = tens value
• Expanded Form: Number = tens + ones
• Verification: Adding parts gives original number
Complete Guide to Expanded Form Test
This summary provides a comprehensive overview of expanded form concepts for the test, covering all essential concepts, methods, and practice strategies.
- Place Value: The value of a digit based on its position in a number
- Tens Place: The second digit from the right; represents groups of 10
- Ones Place: The rightmost digit; represents individual units
- Expanded Form: Writing a number as the sum of its place values (e.g., 45 = 40 + 5)
- Standard Form: The normal way we write numbers (e.g., 45)
- Digit: Any of the numerals 0-9 used to form numbers
- Place Value Rule: Each position has a specific value (ones, tens, hundreds, etc.)
- Tens Rule: Tens digit × 10 = tens value
- Ones Rule: Ones digit × 1 = ones value
- Expanded Form Rule: Number = tens value + ones value
- Verification Rule: Adding expanded parts equals the original number
- Identify Tens Digit: Look at the second digit from the right
- Calculate Tens Value: Multiply tens digit by 10
- Identify Ones Digit: Look at the rightmost digit
- Calculate Ones Value: Ones digit × 1 = ones value
- Write Expanded Form: Number = tens value + ones value
- Verify: Add tens and ones to confirm original number
Simple Examples:
15 = 10 + 5 (1 ten + 5 ones)
23 = 20 + 3 (2 tens + 3 ones)
Intermediate Examples:
47 = 40 + 7 (4 tens + 7 ones)
61 = 60 + 1 (6 tens + 1 one)
Advanced Examples:
89 = 80 + 9 (8 tens + 9 ones)
94 = 90 + 4 (9 tens + 4 ones)
- Position Recognition: Tens are always the second digit from the right
- Multiplication Shortcut: Just add a zero to the tens digit (e.g., 3 → 30)
- Visual Aid: Use base-10 blocks to see tens and ones physically
- Count by Tens: Practice counting by 10s to understand tens place
- Verification Habit: Always add parts to check your answer
- Position Confusion: Mixing up tens and ones places
- Multiplication Error: Forgetting to multiply tens digit by 10
- Zero Mistake: Forgetting to add a zero when writing tens value
- Verification Neglect: Not checking if expanded form adds to original
- Single Digit Confusion: Thinking single digits have tens
- "Right to Left": Ones on the right, tens to the left
- "Tens Times Ten": Tens digit × 10
- "Ones Stay Alone": Ones digit × 1
- "Add to Check": Always add parts to verify
- "Groups of Ten": Tens represent how many groups of 10
- Understanding place value is fundamental to all math operations
- Expanded form shows the actual value of each digit
- Every two-digit number can be broken into tens and ones
- Verification builds confidence and prevents errors
- Practice with various numbers strengthens place value understanding