I Get Percent, But What's the Percent of Change?
Friday September 12, 2008
My students seem to understand that percent is really just a ratio that compares a number to a 100. They also seem to adhere to the rule of moving decimal points to change a percent to a decimal number, in other words 65/100 is quickly converted to 0.65 as they simply move the decimal two places to the left, so quite quickly they realize that 65% is both 0.65 and 65/100. Then comes the percent of change. Head scratching is the initial response. However, they quickly grasp the concept with a quick overview and some time to practice.
How about you? If you're like me, you're up and down with weight, so here's a problem for you:
Let's say I weigh 150 pounds and I lost 25 pounds and I want to know my percentage of body weight loss.
Answer is here!
See also, the Percent Calculator.
Comments
Your “answer is here” answer is wrong for the first part. You show:
175 to 200 — We have an increase of 25 and subtracted to find out the amount of change.
Next, we will divide the amount of change by our original amount.
25 ÷ 200 = 0.125
Now we need to change the decimal to a percent by multiplying 1.125 by 100:
12.5%
We now know that the percentage of change which in this case is an increase from 175 to 200 is 12.5%
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This was wrong. The % change (increase) was actually 14.3% NOT 12.5% as the orginal mass was 175 lb not 200 lb. (175 lb * 0.143 = 25 lb). This was the increase from the original mass of 175 lb.
Ya! There is a mix of original amount and the change in your answer.
lol i need help