Percentage

When any value increases by

1. 10%, it becomes 1.1 times of itself. (since 100+10 = 110% = 1.1)
2. 20%, it becomes 1.2 times of itself.
3. 36%, it becomes 1.36 times of itself.
4. 4%, it becomes 1.04 times of itself.

When any value decreases by

1. 10%, it becomes 0.9 times of itself. (Since 100-10 = 90% = 0.9)
2. 20%, it becomes 0.8 times of itself
3. 36%, it becomes 0.64 times of itself
4. 4%, it becomes 0.96 times of itself.