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← More Shoes - Visualizing Algebra

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Showing Revision 3 created 05/24/2016 by Udacity Robot.

  1. We know if we use 100%, the company will keep it's 200 pairs of shoes. We want
  2. to increase this number. So we need to multiply by a number bigger than 100%.
  3. They want to increase the inventory by 25%. So, we should multiply by 125%. So,
  4. let's actually see this problem worked out. I want to take 125% of the
  5. inventory, so I have 125% of is times the inventory, which is 200 pairs of shoes
  6. from my company. I know percent means divide by 100, so I move the decimal point
  7. 2 places to the left. I have 1.25 times 200. When I multiply, I get 250 pairs of
  8. shoes. Okay, this is great. And we can actually make sense of this another way.
  9. We can think of 200 as four 50's. Each 50 is one-quarter, or 25% of 200. If I
  10. want to increase 200 by 25%, I'm going to add another 50. So I have 50 and 50,
  11. which is 100. I have another 100, which is 200. And 50 more, which is 250. If
  12. you could reason through percentages like that in your head, that's great. If
  13. not, you can always rely on the math.