Lora's phone records data for screen time each week. Last week, she used 840 minutes. This week, Lora used 504 screen time minutes on the phone. Calculate the percent decrease in screen time this week.
To find the percent decrease, we need to find the difference between the two values, divide that difference by the original value, and multiply by 100.
The difference between the two values is 840 - 504 = 336 minutes.
Dividing the difference by the original value gives us 336 / 840 = 0.4.
Multiplying by 100 gives us 0.4 * 100 = 40.
Thus, there was a 40% decrease in screen time this week.