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Math help please
Old 01-23-2021, 11:38 AM
  #1

This is so embarrassing. How soon we forget.

If I divide the old value by the new value, do I get the percent of increase?


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Old 01-23-2021, 11:49 AM
  #2

Say 20 divided by a hundred.
That would be .2, not sure that gives a percentage of increase.

The original value is 20% the new value.


100 divide by 20 would be 5. So it sold 5 times its original value.

I think the percentage of increase would be 4 or 5 hundred?

Iím sure that someone will have the answer.
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Old 01-23-2021, 11:57 AM
  #3

Other way around I think.

100 to 120 is a 20% increase. 120/100 is 1.2. . Drop the one, which leaves a 20% increase.

100/120 is 0.83333, which is 83%. It is saying 100 is 83% of 120. Not the same thing as a % increase.

I hope I have this right!
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Old 01-23-2021, 12:53 PM
  #4

Thanks, but Iím just not understanding your explanations. So I googled (which I should have done in the first place, sorry). I get it now. I should have subtracted to find the change first.
Quote:
How to Calculate Percentage Increase

Subtract final value minus starting value
Divide that amount by the absolute value of the starting value
Multiply by 100 to get percent increase
If the percentage is negative, it means there was a decrease and not an increase.
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Google it
Old 01-23-2021, 12:55 PM
  #5

I've just started using online percent calculators. Either search for percent calculator or percent increase- you'll find lots of options. If working with awkward numbers I try it first with easy numbers like 20, 50, 100 to make sure I'm entering the numbers correctly


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Old 01-23-2021, 01:22 PM
  #6

Okay, so according to your research I think my example would be

100 (final)-20(original)= 80

80 divided by 20 is 4

4 x 100 is 400

so 400%

Is that how you read that?

So my guess of 4 or 500% was maybe correct.

My first math problem above was using your formula.

I haven't taught above 3rd grade for 25 years.
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Old 01-23-2021, 05:10 PM
  #7

First find how much increase there was by subtracting the old value from the new value.

Now divide that amount of increase by the old value.

Example:
old value was $150
New value is $195
Amount of increase is $195 - 150 = 45

Now divide 45 by 150
45/150 = .30, so there was a 30% increase in the value.

Yes, amiga, your googling is correct, as well as the explanation of increase/decrease.
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"There's an app for that!"
Old 01-23-2021, 05:15 PM
  #8

I actually used to teach that, but a few (?) years down the road, and my brain is mush!

I found an app a long time ago that figures out percentages for discounts and such. I'm okay with the basic percentages that end in '0', but the app has saved me many times when I've been shopping and I come across one of those oddball percentage sales... 36% off! HUH? Without the app, I have to round it off. At least I still remember what 'rounding off' means!

Oh! The app is called "Sale Price Discount Calculator" I found this image of the screen.
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