## Real World Applications – Algebra I

### Topic

Why is Absolute Value Useful?

### Student Exploration

Other than in the Algebra world, absolute value is talked about and applied in other disciplines and careers. A geophysicist uses absolute value to look at the total amount of energy used. In an energy wave, there are both negative and positive directions of movement. Another example is when scuba divers discuss their location in regards to sea level. “50 feet below sea level” doesn’t have to be represented as -50 feet. Lastly, when talking about distances in real life, we usually don’t represent distances in negative numbers, even if the distance covered can be represented on a number line or graph. Walking 100 feet to the west can be described as walking +100 feet, and walking 100 feet to the east can be described as walking -100 feet. We don’t represent the distance using positive and negative numbers, but more in direction.

### Extension Investigation

Where do you see absolute value around you? In what cases do we think about positive and negative numbers in calculation, but really just want to know the value of the number?

### Resources Cited

http://answers.yahoo.com/question/index?qid=20100708095654AAC1xBE