Question 337092
10/2 12
10/3 15
10/4 18
10/5 17
10/6 16 
Weekly total ______
Daily average ______ 

Here is the question:
The total for 10/3 is how much higher than the total for 10/2?
a. 3%
b. 12.5%
c. 20%
d. 25% 

The answer is d. 25%.. . but WHY? The only rational I can come up with is 3 is the difference of 15 and 12, and 3 is 25% of 12. But why do I do that to solve this problem? How do I explain this to my students? Most of my students are visual learners so anything I can do to help me understand this, will in turn help them.. 
Thanks so much for taking the time to explain this to me, I really appreciate it.
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Right.
The quantitative gain from 10/2 to 10/3 is 15-12.
That is a gain of 3 from a base of 12
So the percent gain is figured from a base of 12.
You could set up an equation to figure the percent (per one-hundred)
gain as follows:
x/100 = 3/12
x = 100(3/12)
x = 100(1/4)
x = 25
The percent gain is 25%.
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Visualizing this gain with blocks might also be a help.
Compare 12 blocks to 15 blocks to see the gain.
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Keep duplicating the 12 to 15 picture till you have x to 100
The x will be seen to be 25.
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Cheers,
Stan H.