To find the percentage change from 135 to 90, we need to first calculate the difference between the two numbers.

Step 1: Difference = Final Value - Initial Value

Difference = 90 - 135

Difference = -45

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 = |-45|

Absolute Difference = 45

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

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

Percentage Change = (45 / 135) x 100

Percentage Change = 33.33%

Therefore, the percentage change from 135 to 90 is -33.33%. This means that there was a decrease of 33.33% from 135 to 90.