if you know that 7* 8=56 , how can you use the commutative (Order) Property of Multiplication to find the product of 8*7 ?
you just did. The property means that
8 * 7
is exactly the same as
7 * 8
In other words the two factors commute, you can change their order without changing their product. This will be true until you get to multiplying matrices.
http://coolmath.com/prealgebra/06-properties/02-properties-commutative-multiplication-02.htm
Remember back when when you were learning addition you had the commutative property of addition which means
2 + 3
is the same as
3 + 2
Now you are getting the same property for multiplication :)
The commutative property of multiplication states that changing the order of the factors does not change the product. In other words, when multiplying two numbers, you can switch the order of the numbers without affecting the result.
To find the product of 8 * 7 using the commutative property of multiplication, you can simply switch the order of the factors, like this:
7 * 8 = 56
Since the commutative property allows you to switch the factors without changing the product, you can rewrite the expression with the factors reversed:
8 * 7 = 56
Therefore, the product of 8 * 7 is also equal to 56.