Base Ten System: Our number system based on groups of 10
Place Value: The value of a digit based on its position in a number
Regrouping: Changing the grouping of numbers without changing their value
Base Ten Problems: Mathematical challenges involving place value concepts
Number Forms: Standard form (23), expanded form (20 + 3), word form (twenty-three)
Unit: Single cube (1) | Ten: Long rod (10) | Hundred: Flat square (100)
- Read: Carefully read the problem to understand what's being asked
- Identify: Determine which place values are involved
- Model: Use base ten blocks or drawings to represent the problem
- Solve: Perform the required mathematical operation
- Regroup: Exchange blocks as necessary (10 units = 1 ten)
- Check: Verify your answer makes sense in context
- Record: Write your answer in the required format
Blocks shown:
Hundreds: 2 | Tens: 3 | Units: 4
2 hundreds = 200 | 3 tens = 30 | 4 units = 4
200 + 30 + 4 = 234
The number shown is 234.
• Place value: Each position has a specific value
• Counting: Count each type of block separately
• Addition: Combine all place values to get the total
145 = 1 hundred + 4 tens + 5 units | 278 = 2 hundreds + 7 tens + 8 units
Units: 5 + 8 = 13 units | Tens: 4 + 7 = 11 tens | Hundreds: 1 + 2 = 3 hundreds
13 units = 1 ten + 3 units
New totals: Units: 3 | Tens: 11 + 1 = 12 tens | Hundreds: 3
12 tens = 1 hundred + 2 tens
New totals: Units: 3 | Tens: 2 | Hundreds: 3 + 1 = 4 hundreds
145 + 278 = 423
• Regrouping: 10 units = 1 ten, 10 tens = 1 hundred
• Addition: Combine like place values
• Place value: Keep track of each place value separately
321 = 3 hundreds + 2 tens + 1 unit | 187 = 1 hundred + 8 tens + 7 units
We have 1 unit but need to subtract 7 units → Not enough!
Take 1 ten (10 units) and add to 1 unit = 11 units
Now we have: 3 hundreds + 1 ten + 11 units
We have 1 ten but need to subtract 8 tens → Not enough!
Take 1 hundred (10 tens) and add to 1 ten = 11 tens
Now we have: 2 hundreds + 11 tens + 11 units
Units: 11 - 7 = 4 | Tens: 11 - 8 = 3 | Hundreds: 2 - 1 = 1
321 - 187 = 134
• Borrowing: 1 ten = 10 units, 1 hundred = 10 tens
• Subtraction: Take away from like place values
• Regrouping: Break apart higher place value when needed
Base Ten System: Our number system based on groups of 10, fundamental to all arithmetic operations.
- Base Ten System: Number system based on powers of 10 (1, 10, 100, 1000...)
- Place Value: The value of a digit based on its position in a number
- Regrouping: Trading 10 of one place value for 1 of the next higher place value
- Standard Form: Writing numbers with digits (e.g., 234)
- Expanded Form: Breaking numbers into place values (e.g., 200 + 30 + 4)
- Base Ten Problems: Mathematical challenges involving place value concepts
- Only keep up to 9 blocks in each place value position
- 10 units = 1 ten
- 10 tens = 1 hundred
- Always start regrouping from the rightmost place value
- Count systematically to avoid missing or double-counting blocks
- Each place value is 10 times the value of the place to its right
- Read: Carefully read the problem to understand what's being asked
- Identify: Determine which place values are involved
- Model: Use base ten blocks or drawings to represent the problem
- Calculate: Perform the required mathematical operation
- Regroup: Exchange blocks as necessary (10 units = 1 ten)
- Check: Verify your answer makes sense in context
- Record: Write your answer in the required format
Simple: Count blocks: 2 tens + 5 units = 25
Intermediate: Add: 24 + 17 = 41 (with regrouping)
Advanced: Subtract: 321 - 187 = 134 (multiple regroupings)
- Circle groups of 10 when counting to make regrouping easier
- Use different colors for different place values
- Always double-check your counting before recording answers
- Work systematically from left to right or top to bottom
- When subtracting, always check if you have enough blocks in each place value
- Forgetting to regroup when you have 10 or more blocks in a place value
- Miscounting blocks due to poor organization
- Not keeping track of which place value you're working with
- Subtracting the smaller number from the larger regardless of order
"Ten of these become one of those": Remember that 10 of any place value become 1 of the next higher place value.
"Count by place": Always count hundreds first, then tens, then units.
"Right to left": Always start regrouping from the rightmost place value and move left.
Problem 1: Count the blocks: 3 hundreds + 7 tens + 9 units = ?
Problem 2: Add using base ten blocks: 156 + 284 = ?
Problem 3: Subtract using base ten blocks: 432 - 178 = ?
- Read: Read each problem carefully
- Plan: Decide which operation to use
- Model: Use base ten blocks to represent the problem
- Calculate: Perform the operation
- Check: Verify your answer makes sense
- Record: Write your answer in the space provided