Expanded form: Writing a number as the sum of each digit multiplied by its place value.
- Identify the place value of each digit
- Multiply each digit by its place value
- Write the sum of these products
7 is in thousands place (7,000), 3 is in hundreds place (300), 9 is in tens place (90), 2 is in ones place (2)
7 × 1,000 = 7,000; 3 × 100 = 300; 9 × 10 = 90; 2 × 1 = 2
7,392 = 7,000 + 300 + 90 + 2
7,392 = 7,000 + 300 + 90 + 2
• Place value system: Each position has a specific value (ones, tens, hundreds, etc.)
• Digit interpretation: A digit's value depends on its position
• Addition principle: Sum of place values equals the original number
Place value positions: Ones, tens, hundreds, thousands, ten-thousands, hundred-thousands...
2 is in ten-thousands place (20,000), 5 is in thousands place (5,000), 6 is in hundreds place (600), 8 is in tens place (80), 4 is in ones place (4)
2 × 10,000 = 20,000; 5 × 1,000 = 5,000; 6 × 100 = 600; 8 × 10 = 80; 4 × 1 = 4
25,684 = 20,000 + 5,000 + 600 + 80 + 4
25,684 = 20,000 + 5,000 + 600 + 80 + 4
• Place value progression: Each position is 10 times the previous position
• Digit positioning: Reading numbers from left to right determines place value
• Decimal system: Our number system is base 10
Zero placeholders: Zeros in a number still represent their place value (even though the digit is 0)
4 is in ten-thousands place (40,000), 0 is in thousands place (0), 5 is in hundreds place (500), 0 is in tens place (0), 7 is in ones place (7)
4 × 10,000 = 40,000; 0 × 1,000 = 0; 5 × 100 = 500; 0 × 10 = 0; 7 × 1 = 7
40,507 = 40,000 + 0 + 500 + 0 + 7 = 40,000 + 500 + 7
We can omit the zero terms: 40,000 + 500 + 7
40,507 = 40,000 + 500 + 7
• Zero representation: Even though 0×value=0, zeros hold place value
• Position significance: Every position matters for number value
• Simplification rule: We can omit terms with 0 coefficients
Place value: The value of a digit based on its position in a number
Expanded form: Writing a number as a sum of each digit multiplied by its place value
Standard form: The usual way we write numbers (like 5,482)
Base 10 system: Our number system where each position is 10 times the previous position
- Identify positions: Starting from the right, identify the place value of each digit
- Multiply digits: Multiply each digit by its corresponding place value
- Sum results: Add all the products together
- Verify: Check that the expanded form equals the original number
• Place value pattern: Each position is 10 times the previous position
• Expanded form: Sum of each digit multiplied by its place value
• Verification: Adding expanded parts should equal original number
Standard form: The usual way of writing numbers (without showing place values)
8,000 + 300 + 70 + 5 = 8,375
8 is in thousands place, 3 is in hundreds place, 7 is in tens place, 5 is in ones place
Expanded form 8,000 + 300 + 70 + 5 equals standard form 8,375
8,000 + 300 + 70 + 5 = 8,375
• Addition principle: Sum of expanded parts equals standard form
• Place value recognition: Each part corresponds to a specific position
• Verification: Convert back to expanded form to check accuracy
Large number decomposition: Extending place value concept to higher positions (hundred-thousands, millions, etc.)
3 is in hundred-thousands place (300,000), 4 is in ten-thousands place (40,000), 5 is in thousands place (5,000), 6 is in hundreds place (600), 7 is in tens place (70), 8 is in ones place (8)
3 × 100,000 = 300,000; 4 × 10,000 = 40,000; 5 × 1,000 = 5,000; 6 × 100 = 600; 7 × 10 = 70; 8 × 1 = 8
345,678 = 300,000 + 40,000 + 5,000 + 600 + 70 + 8
Add: 300,000 + 40,000 + 5,000 + 600 + 70 + 8 = 345,678 ✓
345,678 = 300,000 + 40,000 + 5,000 + 600 + 70 + 8
• Place value continuation: Pattern continues beyond thousands (ten-thousands, hundred-thousands)
• Systematic approach: Work from left to right, identifying each position
• Verification: Always check by adding the expanded parts
Place value: The value of a digit based on its position in a number
Expanded form: Writing a number as a sum of each digit multiplied by its place value
Standard form: The usual way we write numbers (like 5,482)
Base 10 system: Our number system where each position is 10 times the previous position
- Analyze the number: Count the digits and identify the highest place value
- Identify positions: From right to left, determine each digit's place value (ones, tens, hundreds...)
- Multiply digits: Multiply each digit by its corresponding place value
- Write the sum: Express the number as addition of all the products
- Verify: Add the expanded parts to ensure they equal the original number
• Place value pattern: Each position is 10 times the previous position
• Expanded form: Sum of each digit multiplied by its place value
• Verification: Adding expanded parts should equal original number
• Base 10 relationship: 10 ones = 1 ten, 10 tens = 1 hundred, 10 hundreds = 1 thousand, etc.
234 = ___ + ___ + ___
1,234 = ___ + ___ + ___ + ___
12,345 = ___ + ___ + ___ + ___ + ___
Solutions:
- 234 = 200 + 30 + 4 (2×100 + 3×10 + 4×1)
- 1,234 = 1,000 + 200 + 30 + 4 (1×1000 + 2×100 + 3×10 + 4×1)
- 12,345 = 10,000 + 2,000 + 300 + 40 + 5 (1×10000 + 2×1000 + 3×100 + 4×10 + 5×1)