In this problem, the first thing you do is 10% of 2.50. A trick to finding 10% of any number is to move the decimal point one slot higher, therefore 10% of 2.50 is 0.25. Next, you find the difference between 2.50 and 4.50. this is done by subtracting 2.50 from 4.50. You should get 2.00. Next, you divide 2.00 by 0.25. You should get 8. 0.25 represents 10%, therefore you turn 8 into 80.
The answer is 80%
