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
4 is in thousands place (4,000), 2 is in hundreds place (200), 7 is in tens place (70), 5 is in ones place (5)
4 × 1,000 = 4,000; 2 × 100 = 200; 7 × 10 = 70; 5 × 1 = 5
4,275 = 4,000 + 200 + 70 + 5
4,275 = 4,000 + 200 + 70 + 5
• 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...
1 is in ten-thousands place (10,000), 6 is in thousands place (6,000), 8 is in hundreds place (800), 4 is in tens place (40), 3 is in ones place (3)
1 × 10,000 = 10,000; 6 × 1,000 = 6,000; 8 × 100 = 800; 4 × 10 = 40; 3 × 1 = 3
16,843 = 10,000 + 6,000 + 800 + 40 + 3
16,843 = 10,000 + 6,000 + 800 + 40 + 3
• 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)
5 is in ten-thousands place (50,000), 0 is in thousands place (0), 3 is in hundreds place (300), 0 is in tens place (0), 8 is in ones place (8)
5 × 10,000 = 50,000; 0 × 1,000 = 0; 3 × 100 = 300; 0 × 10 = 0; 8 × 1 = 8
50,308 = 50,000 + 0 + 300 + 0 + 8 = 50,000 + 300 + 8
We can omit the zero terms: 50,000 + 300 + 8
50,308 = 50,000 + 300 + 8
• 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)
9,000 + 400 + 60 + 7 = 9,467
9 is in thousands place, 4 is in hundreds place, 6 is in tens place, 7 is in ones place
Expanded form 9,000 + 400 + 60 + 7 equals standard form 9,467
9,000 + 400 + 60 + 7 = 9,467
• 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.)
4 is in hundred-thousands place (400,000), 5 is in ten-thousands place (50,000), 6 is in thousands place (6,000), 7 is in hundreds place (700), 8 is in tens place (80), 9 is in ones place (9)
4 × 100,000 = 400,000; 5 × 10,000 = 50,000; 6 × 1,000 = 6,000; 7 × 100 = 700; 8 × 10 = 80; 9 × 1 = 9
456,789 = 400,000 + 50,000 + 6,000 + 700 + 80 + 9
Add: 400,000 + 50,000 + 6,000 + 700 + 80 + 9 = 456,789 ✓
456,789 = 400,000 + 50,000 + 6,000 + 700 + 80 + 9
• 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.
345 = ___ + ___ + ___
2,345 = ___ + ___ + ___ + ___
23,456 = ___ + ___ + ___ + ___ + ___
Solutions:
- 345 = 300 + 40 + 5 (3×100 + 4×10 + 5×1)
- 2,345 = 2,000 + 300 + 40 + 5 (2×1000 + 3×100 + 4×10 + 5×1)
- 23,456 = 20,000 + 3,000 + 400 + 50 + 6 (2×10000 + 3×1000 + 4×100 + 5×10 + 6×1)