Place Value: Each digit has a value based on its position (ones, tens, hundreds, thousands...)
Carrying: When adding digits results in 10 or more, carry the extra to the next place value
Regrouping: Another term for carrying, grouping 10 units into the next higher place value
- Align numbers: Place digits in correct columns (ones under ones, tens under tens...)
- Add from right to left: Start with ones place, then tens, hundreds, etc.
- Carry when needed: If sum ≥ 10, write the ones digit and carry the tens digit
- Continue: Repeat for each place value column
• Commutative: Order doesn't matter: 23 + 45 = 45 + 23
• Associative: Grouping doesn't matter: (23 + 45) + 12 = 23 + (45 + 12)
• Identity: Adding zero doesn't change the number: 23 + 0 = 23
• Carrying Rule: When sum ≥ 10, carry to next place value
Two-digit addition: Adding numbers with tens and ones places
- Align numbers by place value
- Add ones place first
- Add tens place (including any carry)
- Write the final sum
7 + 8 = 15, write 5 in ones place, carry 1 to tens place
4 + 2 + 1 = 7 in tens place
47 + 28 = 75
• Place value alignment: Tens aligned with tens, ones with ones
• Carrying rule: When sum ≥ 10, carry to next place value
• Addition principle: Add digits in same place value columns
Three-digit addition: Adding numbers with hundreds, tens, and ones places
6 + 4 = 10, write 0 in ones place, carry 1 to tens place
5 + 7 + 1 = 13, write 3 in tens place, carry 1 to hundreds place
1 + 2 + 1 = 4 in hundreds place
156 + 274 = 430
• Place value alignment: Hundreds, tens, and ones aligned correctly
• Multiple carrying: Can carry multiple times in one problem
• Addition principle: Add digits in same place value columns
Four-digit addition: Adding numbers with thousands, hundreds, tens, and ones places
7 + 5 = 12, write 2 in ones place, carry 1 to tens place
4 + 6 + 1 = 11, write 1 in tens place, carry 1 to hundreds place
2 + 8 + 1 = 11, write 1 in hundreds place, carry 1 to thousands place
1 + 3 + 1 = 5 in thousands place
1,247 + 3,865 = 5,112
• Place value alignment: Thousands, hundreds, tens, and ones aligned correctly
• Multiple carrying: Can carry multiple times in one problem
• Addition principle: Add digits in same place value columns
- Start small: Begin with two-digit numbers before progressing
- Visual aids: Use place value charts and boxes to organize work
- Regular practice: Daily exercises to build fluency
- Self-checking: Always verify answers using inverse operations
• Numbers properly aligned by place value ✓
• Added from right to left ✓
• Carries recorded correctly ✓
• Answer checked ✓
• Digits in correct place value positions ✓
Sum: The result of addition
Addends: Numbers being added together
Carry: Extra amount moved to next place value
Regrouping: Another term for carrying