The Commutative property: By multiplication only

According to the rules of the order of arithmetic operations, in an exercise where there is only one multiplication operation, the order of the numbers can be changed.

Hence we can rearrange the exercise to obtain a round number that will help us later in the solution:

$5\times2\times17=$

Now we solve the exercise from left to right:

$5\times2=10$

$10\times17=170$

We use the substitution property and organize the exercise in the following order:

$5\times2\times5\times2\times5\times2=$

We place parentheses in the exercise:

$(5\times2)\times(5\times2)\times(5\times2)=$

We solve from left to right:

$10\times10\times10=$

$(10\times10)\times10=$

$100\times10=1000$

According to the rules of the order of operations, since the exercise only involves multiplication, the order of the numbers can be changed.

We organize the exercise in such a way that we get a round number as a result of multiplying the first two numbers:

$12\times5\times9=$

We solve the exercise from left to right:

$12\times5=60$

$60\times9=540$

According to the rules of the order of operations, since the exercise only involves multiplication, you can swap the order of the numbers.

We rearrange the numbers to create pairs of multiplication exercises, which will then give us a simpler equation:

$7\times13\times5\times6=(7\times13)\times(5\times6)$

We solve the exercises in parentheses:

$91\times30=2730$