To find the percentage change from 12 to 15, we need to first calculate the difference between the two numbers.

Step 1: Difference = Final Value - Initial Value

Difference = 15 - 12

Difference = 3

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 = |3|

Absolute Difference = 3

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

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

Percentage Change = (3 / 12) x 100

Percentage Change = 25%

Therefore, the percentage change from 12 to 15 is 25%. This means that there was an increase of 25% from 12 to 15.