math question

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JulianMathHelp

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Mr. Wallis took his home design to the copier and enlarged it 400%. What is the area of the diagram now? Show how you know. The area of the original figure is 15 meters. I have a similar problem to this (number changed), and want to know if I'm interpreting the question correctly. Please share with me :)
 
How are you interpreting the question? We can't tell if your interpretation is correct if you don't tell us.
 
Harry_the_cat said:
How are you interpreting the question? We can't tell if your interpretation is correct if you don't tell us.
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Well I think that it means that the new shape's sides are 400% bigger than the old shape's sides, but after asking other people on online sites such as Brainly, a some people are saying it is 400% of the old shape's sides. Could you share your thoughts?
 
What happens if you enlarge something 100%? Is it then 100% of the old shape's sides?
 
500% of the original sides, so I'm correct? However, I checked the answer key to the problem and it was indicating 400% of the old sides, maybe a poor choice of wording from the writer's end? I'm guessing they were trying to refer to scale factor.
 
Yes poor wording if that is what they meant. Maybe if you push 200% when enlarging on a photocopier, it just doubles the sides (or maybe even doubles the area) - not sure. But mathematically it is incorrect either way.
 
What do you mean by "But mathematically it is incorrect either way." Im sorry for asking this, but I want to understand 100%.
 
An increase of 200% doesn't double the sides and it doesn't double the area. I'm just saying that on a photocopier where is says enlarge 200%, I'm not sure what it is programmed to do.
 
For the record if you double the sides of a rectangle which is l x w, then the new area will be (2x) x (2y) = 4xy while the original is xy.
 
JulianMathHelp said:
500% of the original sides, so I'm correct? However, I checked the answer key to the problem and it was indicating 400% of the old sides, maybe a poor choice of wording from the writer's end? I'm guessing they were trying to refer to scale factor.
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Yes, that's what I wrote earlier - ambiguous question. Based on the answer enlarge X% means the new size is X% of the old size.
 
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Each side will be 2x the original sides. That is 4x5 will become 8x10.
 
JulianMathHelp said:
This is confusing. I’m sorry, even with all this help. I can’t understand it fully.
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I don't think anyone can resolve ambiguity "fully", Julian.

On one hand, this exercise involves a photocopier scenario; the student needs to be familiar with such machines, and that's no longer common knowledge. We're in the digital age now, so fancy software options exist to accomplish any interpretation. Common knowledge evolves. The exercise is ambiguous, but, due to boomer bias, "enlarged it 400%" means lengths quadruple.

In math, you'll experience a number of things not used consistently, in course materials or the real world. In a bonafide course, a student has definitions, or they resolve ambiguity at the source. When we practice and can't ask the source, each of us gets to decide. One could work it multiple ways, to be prepared or just for fun.

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