A stock's value decreased by 20%. To the nearest integer, how much must its value increase to return to what it was before it decreased?

To find out how much the stock's value must increase to return to its original value, we can follow these steps:

1. Calculate the amount of the decrease: Multiply the original value of the stock by 20% (or 0.20) to find the decrease amount.
2. Subtract the decrease amount from the original value to find the new value after the decrease.
3. Calculate the difference between the new value and the original value to determine how much the stock's value needs to increase.

Let's assume the original value of the stock is $100.

1. Decrease amount = $100 * 0.20 =$20
2. New value after the decrease = $100 -$20 = $80
3. Increase amount = $100 -$80 = $20

Therefore, the stock's value must increase by $20 to return to what it was before the 20% decrease.