| Negative numbers are weird. | ||
| I like to think of positive and negative numbers | ||
| like the floors of a great big building with lots of basement levels ... | ||
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| Now think about adding and subtracting like elevator rides in that building: | ||
| 1) The first number is the floor where you start. | ||
| 2) The sign that comes after the first number | ||
| says which way the elevator goes. | ||
| + means it goes up, - means it goes down. | ||
| 3) The second number is how many floors you move. | ||
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Example |
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3 - 5 |
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So: 3 - 5 = - 2 |
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| Example | ||
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- 3 - 2 |
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So: - 3 - 2 = - 5 |
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| Example | ||
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- 2 + 5 |
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So: - 2 + 5 = 3 |
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copyright 2005 Bruce Kirkpatrick |
