Place Value Strategy: Breaking apart numbers by their place values (tens and ones) to make addition or subtraction easier
- Separate each number into tens and ones
- Add the tens together
- Add the ones together
- Combine the results
34 = 30 + 4 (3 tens and 4 ones)
25 = 20 + 5 (2 tens and 5 ones)
30 + 20 = 50
4 + 5 = 9
50 + 9 = 59
34 + 25 = 59
34 + 25 = 59
• Place Value: Each digit has a specific place value (tens, ones)
• Separation Rule: Separate numbers into their place values
• Add Like Values: Add tens with tens, ones with ones
Place Value Subtraction: Separating numbers by place values to make subtraction easier by subtracting tens from tens and ones from ones
67 = 60 + 7 (6 tens and 7 ones)
23 = 20 + 3 (2 tens and 3 ones)
60 - 20 = 40
7 - 3 = 4
40 + 4 = 44
67 - 23 = 44
67 - 23 = 44
• Place Value: Each digit has a specific place value (tens, ones)
• Separation Rule: Separate numbers into their place values
• Subtract Like Values: Subtract tens from tens, ones from ones
Word Problems with Place Value: Real-life situations that require breaking apart numbers by place values to solve
Sarah starts with 48 pencils
She gives away 15 pencils
Need to calculate: 48 - 15
48 = 40 + 8 (4 tens and 8 ones)
15 = 10 + 5 (1 ten and 5 ones)
40 - 10 = 30
8 - 5 = 3
30 + 3 = 33
48 - 15 = 33
Sarah has 33 pencils left
Sarah has 33 pencils left
• Problem Analysis: Identify numbers and operation needed
• Place Value Strategy: Break apart numbers by their place values
• Contextual Answer: Provide answer in context of the word problem
Place Value Strategy: A method of solving addition and subtraction problems by separating numbers into their place values (tens and ones)
Place Value: The value of a digit based on its position (ones, tens, hundreds)
Tens: Groups of 10 (10, 20, 30, etc.)
Ones: Individual units (1, 2, 3, etc.)
Decompose: Breaking apart a number into its place values
- Identify numbers: Recognize the numbers to be added or subtracted
- Break apart: Separate each number into tens and ones
- Group like values: Add or subtract tens with tens, ones with ones
- Combine results: Put the tens and ones back together
- Write answer: Express the final result
• Separate first: Always break apart numbers into tens and ones
• Group like values: Add or subtract tens with tens, ones with ones
• Combine results: Put the final tens and ones back together
• Place value matters: Each digit has a specific value based on its position
• Check your work: Verify by using standard methods
Concepts: Place value strategy involves breaking apart numbers by their place values (tens and ones) to make addition and subtraction easier.
Rules: 1) Break apart numbers into tens and ones, 2) Group like values together, 3) Combine results.
Examples: 34+25=(30+20)+(4+5)=50+9=59, 67-23=(60-20)+(7-3)=40+4=44.
Methods: Decomposition, grouping like values, recombination.
Tips: Separate first, group alike, combine, check work.
Advanced Place Value Addition: When adding tens and ones results in more than 9 ones, we may need to regroup
56 = 50 + 6 (5 tens and 6 ones)
38 = 30 + 8 (3 tens and 8 ones)
50 + 30 = 80
6 + 8 = 14
14 ones = 1 ten + 4 ones
So 80 + 14 = 80 + 10 + 4 = 90 + 4
90 + 4 = 94
56 + 38 = 94
56 + 38 = 94
• Place Value Addition: Add tens with tens, ones with ones
• Regrouping: When ones sum ≥ 10, convert to tens and ones
• Sequential Addition: Work from largest place value to smallest
Advanced Place Value Subtraction: When subtracting ones results in needing to borrow from tens
84 = 80 + 4 (8 tens and 4 ones)
57 = 50 + 7 (5 tens and 7 ones)
4 - 7: Since 4 < 7, we need to borrow from tens
84 = 70 + 14 (7 tens and 14 ones)
70 - 50 = 20
14 - 7 = 7
20 + 7 = 27
84 - 57 = 27
84 - 57 = 27
• Place Value Subtraction: Subtract tens from tens, ones from ones
• Borrowing: When ones top < ones bottom, borrow from tens
• Verification: Check by adding the answer to the subtracted number
Place Value Strategy: A method of solving addition and subtraction problems by separating numbers into their place values (tens and ones)
Place Value: The value of a digit based on its position (ones, tens, hundreds)
Decompose: Breaking apart a number into its place values
Compose: Putting place values back together to form a number
Regroup: Converting between place values when necessary
- Identify numbers: Recognize the numbers to be operated on
- Decompose: Separate each number into tens and ones
- Check conditions: Determine if regrouping is needed
- Operate on like values: Add or subtract tens with tens, ones with ones
- Handle regrouping: Convert between place values if needed
- Compose result: Put the final answer together
- Verify: Check by using standard methods
• Decomposition: AB = A×10 + B (separate into tens and ones)
• Like value operations: Add/subtract tens with tens, ones with ones
• Regrouping condition: When ones ≥ 10, convert to tens and ones
• Borrowing condition: When ones top < ones bottom, borrow from tens
• Verification method: Check by using standard addition/subtraction
- Always separate numbers into tens and ones first
- Only add/subtract like place values (tens with tens, ones with ones)
- When ones sum ≥ 10, convert to tens and ones
- When subtracting and not enough ones, borrow 1 ten = 10 ones
- Check your work by using standard methods
- Remember: 10 ones = 1 ten
Definitions: Place value strategy involves breaking apart numbers by their place values (tens and ones) to make operations easier.
Laws: 1) Decompose into place values, 2) Operate on like values, 3) Regroup when necessary.
Methods: Identify → Decompose → Operate → Regroup → Compose → Verify.
Examples: 34+25=(30+20)+(4+5)=59, 56+38=(50+30)+(6+8)=80+14=94.
Tips: Separate first, group alike, check work, practice with visual aids.
Key Notes: Place value strategy makes complex operations more manageable by focusing on individual place values.