01 Key Concepts
Sum
The result of adding numbers together.
Carrying
When a column adds to 10 or more, carry the extra 'ten' to the next column to the left.
Commutative Property
Order does not matter: a + b = b + a.
Associative Property
Grouping does not matter: (a + b) + c = a + (b + c).
Adding Zero
Any number plus 0 equals itself (the identity property).
03 Key Formulas
- Sum = addend1 + addend2 + ...
04 Solved Examples
Example 1 Add 247 + 158.
- Ones: 7+8=15, write 5, carry 1.
- Tens: 4+5+1(carry)=10, write 0, carry 1.
- Hundreds: 2+1+1(carry)=4.
Answer: 405
Example 2 Add 3,684 + 2,197.
- Ones: 4+7=11, write 1, carry 1.
- Tens: 8+9+1=18, write 8, carry 1.
- Hundreds: 6+1+1=8.
- Thousands: 3+2=5.
Answer: 5,881
Example 3 Use the commutative property to check 45 + 32 = 32 + 45.
- 45 + 32 = 77.
- 32 + 45 = 77.
- Both orders give the same sum.
Answer: Confirmed: 77 = 77
05 Practice Questions
136 + 47 = ?
83
2128 + 356 = ?
484
3509 + 291 = ?
800
41,254 + 3,678 = ?
4,932
5What property says 5+9 = 9+5?
Commutative property
📄 Addition — Downloadable Worksheet
10 questions with a full answer key. Grab the PDF to print, or try the interactive version in your browser.