"A TV is on sale at 30% off for $420"
What was the original price of the TV?
Well if you start to calculate first off you are sooner or later going to figure out that in order for it to be 420 the answer has to be bigger than 1,000. If you get to 1,200 and calculate 30 percent off of it it the answer is 360 so a ballpark quesstiminate would be to go two more hundredths up. Therefore 30 percent of 1,400 is 420