Name
Date
Lesson 1
Reteach
Addition Properties and Subtraction Rules
We use addition properties and subtraction rules to add and subtract.
These properties and rules help us add numbers mentally. There are
three main properties of addition and two subtraction rules to keep in
mind as you add and subtract.
Addition Properties
Associative Property
Commutative Property
The order in which numbers The way in which numbers
are added does not change are grouped when added
does not change the sum.
the sum.
Example
(6 + 5) + 2
Example
3+1=4
11
1+3=4
+2
6 + (5 + 2)
6+
13
Identity Property
The sum of any number
and 0 is the number.
Example
9+0=9
7
0+9=9
13
Subtraction Rules
When you subtract any number
from itself, the result is 0.
Examples
7-0=7
Examples
8-8=0
5-0=5
4-4=0
Algebra Find each unknown. Identify the property or rule used.
5 Associative
Identity
1. 5 + (3 + 4) = (3 + 4) +
2.
7
+0=7
3. 6 -
6
=0
subtraction
4. 2 -
0
=2
subtraction
5. (3 + 2) + 5 = 3 + (2 +
10
5)
Associative
Grade 4 • Chapter 2 Add and Subtract Whole Numbers
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When you subtract 0 from any
number, the result is the number.