Properties are special qualities of something.
Addition and multiplication have special qualities that help you solve
problems mentally=
MENTAL MATH!!
Commutative Properties
ANY ORDER!
You can add or multiply in any order and get the same answer.
5 + 3 = 8 4 x 9 = 36
Or
3 + 5 = 8 9 x 4= 36
Does it work for subtraction?
Does it work for division?
Associative Properties
GROUP NUMBERS!
You can group numbers in different ways when adding or multiplying and get the same answer.
4 + (6 + 7) = 17 2 x (5 x 13) = 130
or
(4 + 6) + 7 = 17 (2 x 5) x13 = 130
Does it work for subtraction?
Does it work for division?
Distributive Properties
BREAK APART NUMBERS!
You can multiply a sum by a factor by finding two separate products and adding the products.
4 x 12 = 48
4 x (10 + 2) = 48
(4 x 10) + (4 x 2) = 48
Does it work for subtraction?
Does it work for division?
Let’s Practice!Solve using mental math. Name the property
you used!200 x 36 x 5 =
25 + 634 + 75 =
3 x 29 =
Use compensation to find answers mentally!
58 + 93 = (58 + 3) + (93 – 3)
= 61 + 90
= 151
352 – 49 =
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