1. Addition and Subtraction
Numbers you add are called addends.
The answer to an addition problem is called the sum.
= 5
addend + addend
= sum
Addends can change position without affecting the sum = 5 and = 5
This is called the commutative property of addition.

2. The commutative property does NOT apply to subtraction.
The first number of a subtraction problem is called the minuend.
The number you take away is called the subtrahend.
The answer is called the difference.
= 3
minuend - subtrahend
= difference
The commutative property does NOT apply to subtraction.

3. When adding or subtracting you must be sure to line up place value positions.
Since we will often be adding decimal numbers, write in any implied decimals first, then line them up. This will line up the place values. .
+ 73,582.2
390,496

4. Annex any zeros that are needed as place holders.
390,496
+ 73,582.2

5. Add.
Don’t forget the decimal in your answer.
Regroup as needed. 4 1 5 . . 1+
390,496 1+ 1+
+ 73,582.2 4 6 4, 7 8 2

6. Since we will often be subtracting decimal numbers, write in any implied decimals first, then line them up. This will line up the place values. Annex any zeros that are needed as place holders. .
- 73,582.2
390,496 0

7. Borrow, or regroup as needed.
Subtract.
Don’t forget the decimal in your answer. 9 8 10 14 5 10 . .
390,496
- 73,582.2 3 1 6, 9 1 3 8

8. Addition and Subtraction Guided Practice1
Addition and Subtraction Guided Practice
0.078 . 6 8

9. 2 4 10 10 12
7,511.2 .
- 6,421.4 1, 8 9 8

10. 3 9 9 3 10 10 10
26,264 .
000 2 6, 2 6 3 9 9 8

11. 4 1+ 1+ 1+ 1+
5,366,895.8 .
5,36 7, 5 3 2 1

12. 5
499.94
+ 485,677
, ,176.94
1+ 1+ 1+

13. 6
0.08 1+

14. Addition and Subtraction Independent Practice1 2
1, ,735.12

15. 3
864.1 – 675.9 4
4,099,728 – 53,946 5
2,562, 6

16. 7
5, – 8
5 + 4,530,302 9 10
681,026.4 – 8.9