Input: To calculate the percentage change from 1000000 to 3000000, we need to follow the below steps:

Step 1: Find the difference between the two numbers.

3000000 - 1000000 = 2000000

Step 2: Divide the difference by the original number.

2000000 / 1000000 = 2

Step 3: Multiply the result by 100 to get the percentage change.

2 * 100 = 200%

Therefore, the percentage change from 1000000 to 3000000 is 200%. This means that the output has increased by 200% compared to the input. Alternatively, we can say that the output is three times the input or has increased by a factor of 3.

In conclusion, to calculate the percentage change from one number to another, we need to find the difference, divide it by the original number, and multiply the result by 100. This formula can be used to calculate percentage changes in various scenarios, such as sales growth, population increase, or inflation rate.