Expanded notation for Grade 3: Writing a number as the sum of each digit multiplied by its place value (tens, ones).
- Identify the place value of each digit (tens, ones)
- Multiply each digit by its place value
- Write the sum of these products
• Write 34 in expanded notation
• Write 79 in expanded notation
• Write 26 in expanded notation
In 58: 5 is in tens place, 8 is in ones place
5 × 10 = 50; 8 × 1 = 8
Combine all values: 50 + 8
58 = 50 + 8
• Place value system: Each position represents a power of 10
• Expanded form: Express number as sum of place values
• Value calculation: Digit × Place value = Component value
Expanded notation with zero: When a number has zero in the ones place, we still include it in expanded form.
• Write 30 in expanded notation
• Write 70 in expanded notation
• Write 90 in expanded notation
In 40: 4 is in tens place, 0 is in ones place
Even though 0 × 1 = 0, we include it in the expanded form to maintain place value structure
4 × 10 = 40; 0 × 1 = 0
40 = 40 + 0
• Zero inclusion: Include zeros in expanded notation to maintain place value structure
• Place holding: Zeros hold positions even when they contribute zero value
• Completeness: Every digit position should be represented
Three-digit expanded notation: Writing a three-digit number as the sum of hundreds, tens, and ones.
• Write 528 in expanded notation
• Write 691 in expanded notation
• Write 405 in expanded notation
In 347: 3 is in hundreds place, 4 in tens, 7 in ones
3 × 100 = 300; 4 × 10 = 40; 7 × 1 = 7
Combine all values: 300 + 40 + 7
347 = 300 + 40 + 7
• Three-digit numbers: Include hundreds, tens, and ones
• Place value system: Each position represents a power of 10
• Expanded form: Express number as sum of place values
Place Value: The value of a digit based on its position in a number (ones, tens, hundreds).
Expanded Form: Writing a number as the sum of each digit's value.
Standard Form: The normal way we write numbers using digits.
Digit: Any of the symbols 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 used to write numbers.
- Identify digits: Look at each digit in the number
- Determine place values: Identify the value of each position (ones, tens, hundreds)
- Multiply: Multiply each digit by its place value
- Add: Sum all the products to get expanded form
- Verify: Check that your expanded form adds up to the original number
Numbers with zeros in expanded notation: When a number has zero in any place value, we still include that place in expanded form.
• Write 307 in expanded notation
• Write 802 in expanded notation
• Write 400 in expanded notation
In 508: 5 is in hundreds place, 0 in tens, 8 in ones
Even though 0 × 10 = 0, we include it in the expanded form to maintain place value structure
5 × 100 = 500; 0 × 10 = 0; 8 × 1 = 8
508 = 500 + 0 + 8
• Zero inclusion: Include zeros in expanded notation to maintain place value structure
• Place holding: Zeros hold positions even when they contribute zero value
• Completeness: Every digit position should be represented
Mixed practice: Working with various numbers helps solidify understanding of place value concepts.
642 = 600 + 40 + 2
309 = 300 + 0 + 9
750 = 700 + 50 + 0
Follow the same method for each number: identify place values, multiply by place value, sum components
Check that the expanded form adds up to the original number
Numbers with trailing zeros still include those zeros in expanded form
309 = 300 + 0 + 9
750 = 700 + 50 + 0
642 = 600 + 40 + 2
309 = 300 + 0 + 9
750 = 700 + 50 + 0
• Consistent method: Same process applies to all numbers
• Zero inclusion: Include zeros in expanded form to maintain place value structure
• Verification: The sum of components should equal the original number
Place Value: The value of a digit based on its position in a number (ones, tens, hundreds).
Expanded Form: A number written as the sum of each digit multiplied by its place value.
Standard Form: The usual way we write numbers using digits without showing place value breakdown.
Digit: Any of the symbols 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 used to write numbers.
Place Value Chart: A visual representation showing the value of each position in a number.
- Read the number: Identify each digit and its position
- Assign place values: Determine the value each digit position represents
- Multiply digits by place values: Calculate each digit's contribution
- Write as addition: Combine all components with plus signs
- Verify: Check that the sum equals the original number
• Ones place: 1 = 1
• Tens place: 1 = 10
• Hundreds place: 1 = 100
• Pattern: Each place value is 10 times the previous one
Questions & Answers
Question: Why do we need to learn expanded notation? It seems harder than just writing the number.
Answer: Great question! Expanded notation helps you understand what numbers really mean:
- Understand numbers: It shows you that 234 is made of 200 + 30 + 4
- Easier math: It makes addition and subtraction easier later
- Big numbers: It prepares you for bigger numbers in higher grades
- Real life: It helps count things like money and groups of items
Expanded notation builds the foundation for understanding how our number system works!
Question: My child gets confused with the expanded form of numbers like 405. How can I help them understand?
Answer: Here are effective strategies to help with numbers containing zeros:
- Visual aids: Use place value charts to clearly show where each digit goes
- Verbal explanation: Say "There are 0 tens" rather than skipping the place
- Physical objects: Use base-10 blocks to show empty places
- Pattern recognition: Emphasize that every position must be accounted for
Example: In 405, emphasize "4 hundreds, 0 tens, 5 ones" even though there are 0 tens. The zero still holds the place and appears in expanded form as 0.
Practice with numbers like 102, 304, and 500 to build confidence with zeros.
Question: Are there more place values beyond hundreds? What comes next?
Answer: Yes! The place value system continues:
- Thousands: Fourth digit from right (1,000)
- Ten thousands: Fifth digit from right (10,000)
- Hundred thousands: Sixth digit from right (100,000)
- Pattern continues: Each place is 10 times the previous one
Example: In 1,234:
1 is in thousands place (1,000), 2 in hundreds (200), 3 in tens (30), 4 in ones (4)
For now, focus on hundreds, but know that the same pattern applies to larger numbers!