To find the percentage change from 800 to 1000, we need to first calculate the difference between the two numbers.

Step 1: Difference = Final Value - Initial Value

Difference = 1000 - 800

Difference = 200

Step 2: Next, we need to find the absolute value of the difference. This is because percentage change is always calculated as a positive value.

Absolute Difference = |Difference|

Absolute Difference = |200|

Absolute Difference = 200

Step 3: Now, we can calculate the percentage change using the formula:

Percentage Change = (Absolute Difference / Initial Value) x 100

Percentage Change = (200 / 800) x 100

Percentage Change = 25%

Therefore, the percentage change from 800 to 1000 is 25%. This means that there was an increase of 25% from 800 to 1000.