Place value: The value of a digit depends on its position in a number
Hundreds place: Third digit from the right (worth 100s)
Tens place: Second digit from the right (worth 10s)
Ones place: First digit from the right (worth 1s)
- Identify the position of the digit
- Know the value of each position
- Multiply the digit by its position value
- State the result
In 473, the digit 7 is in the tens place
The tens place has a value of 10
7 × 10 = 70
The digit 7 in 473 has a value of 70
The value of the digit 7 in 473 is 70 because it is in the tens place
• Position identification: Count from right to left (ones, tens, hundreds)
• Value calculation: Digit × Place value
• Verification: Check that all place values sum to original number
Expanded form: Writing a number as the sum of the value of each digit
5 is in the hundreds place: 5 × 100 = 500
8 is in the tens place: 8 × 10 = 80
2 is in the ones place: 2 × 1 = 2
582 = 500 + 80 + 2
582 in expanded form is 500 + 80 + 2
• 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
Base ten blocks: Visual representations of place value (flats, rods, units)
Flats: Represent 100 (10 × 10)
Rods: Represent 10 (10 × 1)
Units: Represent 1
3 is in the hundreds place: need 3 flats (3 × 100 = 300)
4 is in the tens place: need 4 rods (4 × 10 = 40)
7 is in the ones place: need 7 units (7 × 1 = 7)
347 = 3 flats + 4 rods + 7 units = 300 + 40 + 7
347 is represented by 3 flats (hundreds), 4 rods (tens), and 7 units (ones)
• Block correspondence: Each digit corresponds to a specific type of block
• Visual representation: Use concrete materials to show abstract concepts
• Value confirmation: Verify that blocks represent the correct number
Place value: The value of each digit based on its position in a number
Base ten system: Our number system based on groups of 10
Expanded form: Writing numbers showing the value of each digit
- Identify positions: Hundreds, tens, ones (right to left)
- Recognize values: Each position is worth 10 times the one to its right
- Calculate values: Multiply digit by its place value
- Verify: Check that values sum to original number
Number composition: Building a number from its place value parts
2 hundreds = 2 × 100 = 200
5 tens = 5 × 10 = 50
8 ones = 8 × 1 = 8
200 + 50 + 8 = 258
The number made up of 2 hundreds, 5 tens, and 8 ones is 258
• Component identification: Recognize each place value part
• Value calculation: Convert each part to its numerical value
• Summation: Add all values to get the final number
Zero in place value: When a place has zero, it contributes nothing to the total value
The hundreds place has 6: 6 hundreds
The tens place has 0: 0 tens (no tens)
The ones place has 4: 4 ones
604 has 6 hundreds, 0 tens, and 4 ones
In the number 604, there are 6 hundreds, 0 tens, and 4 ones
• Zero recognition: Zero in any place means no units of that value
• Place identification: Each position has a specific value
• Value contribution: Zero contributes nothing to the total value
Number sense: Understanding the value, relationships, and operations of numbers
Base-10 system: Our number system based on groups of 10
Expanded form: Writing numbers showing the value of each digit
- Understand position: Know that position determines value
- Recognize values: Each place is 10 times the value of the place to its right
- Calculate contributions: Multiply each digit by its place value
- Compose/decompose: Build and break down numbers
- Verify accuracy: Check that all parts sum to original number
• Position importance: Where a digit sits determines its value
• Base ten relationship: Each place is 10 times the place to its right
• Zero handling: Zero holds place but contributes no value
• Verification: Check that place values sum to original number
• Systematic approach: Work from right to left when identifying places
• Hundreds: Worth 100 (10 × 10 × 1)
• Tens: Worth 10 (10 × 1)
• Ones: Worth 1 (the base unit)
Examples: Each number demonstrates place value relationships.
- 473: 4 hundreds (400) + 7 tens (70) + 3 ones (3) = 473
- 582: 5 hundreds (500) + 8 tens (80) + 2 ones (2) = 582
- 347: 3 hundreds (300) + 4 tens (40) + 7 ones (7) = 347
- 604: 6 hundreds (600) + 0 tens (0) + 4 ones (4) = 604