Associative Property: Addition only

According to the rules of the order of operations, you can use the substitution property and start the exercise from right to left to calculate comfortably:

$8+12=20$

Now we obtain the exercise:

$7+20=27$

According to the rules of the order of operations, you can use the substitution property and organize the exercise in a more convenient way for calculation:

$94+6+12=$

Now, we solve the exercise from left to right:

$94+6=100$

$100+12=112$

According to the rules of the order of operations, we solve the exercise from left to right in the most convenient way for the calculation:

$13+37=50$

$50+45=95$

According to the rules of the order of operations, you can use the substitution property and start the exercise from right to left to comfortably calculate:

$31+19=50$

$48+50=98$

In order to simplify our calculations we try to add numbers that give us a round result.

Let's keep in mind that:

$113+57=170$

$59+71=130$

Now we have a more manageable exercise to solve:

$170+130=300$