Mikey bought himself a new video game on sale.

he paid $35 for the video game, it was marked 30% off.

his mom asked him what the video game was priced at originally.

In percentage: 100=30% +70%
Now, after taking 30% off the original price, what Mikey paid for that game must be 70% of the original price. The easiest way to find this, in this scenario, is finding what 10% is and then multiplying that number to get 100%.

$35/7=$5
$5*10=$50 
The game was originally priced at $50.