Expanded form: Writing a number as the sum of the value of each digit
Standard form: Writing a number with digits (347)
- Identify the hundreds digit
- Identify the tens digit
- Identify the ones digit
- Multiply each digit by its place value
- Write as a sum
3 is in the hundreds place: 3 × 100 = 300
4 is in the tens place: 4 × 10 = 40
7 is in the ones place: 7 × 1 = 7
347 = 300 + 40 + 7
347 in expanded form is 300 + 40 + 7
• Place value multiplication: Multiply each digit by its place value
• Sum formation: Add all place values together
• Verification: Check that expanded form sums to original number
Converting expanded to standard: Adding the place values to get the original number
500 (hundreds), 20 (tens), 8 (ones)
500 + 20 + 8 = 528
The number is 528
528 in expanded form: 500 + 20 + 8 ✓
500 + 20 + 8 represents the number 528
• Place value addition: Add hundreds, tens, and ones separately
• Standard formation: Combine place values to form the number
• Verification: Check by converting back to expanded form
405 → ___ → ___
Conversion practice: Moving between standard and expanded forms
405: 4 hundreds (400), 0 tens (0), 5 ones (5)
405 = 400 + 0 + 5
400 + 0 + 5 = 405
Original number: 405, final number: 405 ✓
405 → 400 + 0 + 5 → 405
• Zero handling: Include zeros in expanded form
• Consistent conversion: Both directions should yield the same number
• Verification: Round-trip conversion confirms accuracy
Place value: The value of a digit based on its position in a number
Expanded form: Breaking a number into the sum of each digit's value
Standard form: The normal way we write numbers with digits
- Identify digits: Recognize hundreds, tens, and ones
- Determine place values: Multiply each digit by its position value
- Write as sum: Add all place values together
- Verify: Check that sum equals original number
Zero handling: When a place value has zero, include it in expanded form
6 is in the hundreds place: 6 × 100 = 600
0 is in the tens place: 0 × 10 = 0
3 is in the ones place: 3 × 1 = 3
603 = 600 + 0 + 3
603 in expanded form is 600 + 0 + 3
• Zero inclusion: Always include zero place values in expanded form
• Place value preservation: Zeros maintain digit positions
• Verification: 600 + 0 + 3 = 603 ✓
Multiple representations: Showing the same number in different forms
742 (already in standard form)
7 hundreds = 700, 4 tens = 40, 2 ones = 2
742 = 700 + 40 + 2
700 = seven hundred, 40 = forty, 2 = two
Combined: seven hundred forty-two
700 + 40 + 2 = 742 ✓
742 in standard form: 742, in expanded form: 700 + 40 + 2, in word form: "seven hundred forty-two"
• Consistent value: All forms represent the same number
• Systematic conversion: Convert step by step
• Verification: Check that all forms equal the original number
Number sense: Understanding the value and relationships between numbers
Place value system: Our base-10 number system where position determines value
Expanded notation: Writing numbers showing the value of each digit
- Identify place values: Recognize hundreds, tens, and ones
- Apply multiplication: Multiply each digit by its place value
- Form the sum: Write as addition problem
- Verify accuracy: Check that sum equals original number
- Practice conversion: Work in both directions
• Multiplication step: Multiply each digit by its place value
• Zero inclusion: Always include zero place values in expanded form
• Sum formation: Write as addition problem using plus signs
• Verification: Check that expanded form sums to original number
• Fluency: Practice until conversions become automatic
• Standard form: 347 (with digits)
• Expanded form: 300 + 40 + 7 (as sum of place values)
• Word form: Three hundred forty-seven (with words)
Examples: Each representation shows the same value differently.
- Standard: 347 → Expanded: 300 + 40 + 7 → Verification: 300 + 40 + 7 = 347
- Standard: 528 → Expanded: 500 + 20 + 8 → Verification: 500 + 20 + 8 = 528
- Standard: 405 → Expanded: 400 + 0 + 5 → Verification: 400 + 0 + 5 = 405
- Standard: 603 → Expanded: 600 + 0 + 3 → Verification: 600 + 0 + 3 = 603