Friday, September 12, 2014

Mean Average Deviation

Mean Average Deviation:

The average distance each number is from the mean.

Mean:

The middle found by adding all the numbers of a data set together and then dividing by the amount of numbers.

Distance:

The positive difference between two numbers on a number line.


How do I find mean average deviation?

1.  First find the mean by adding all the numbers and dividing the sum by the amount of numbers.
2.  Subtract the mean from each number in the data set.
3.  Use absolute value to represent the distance of each difference.  This makes them all positive.
4.  Add all those numbers together and then divide by the amount of numbers in the data set.

Thursday, September 11, 2014

Sales Tax

1.  What is a sales tax?

2.  What does the sales tax of Texas pay for?

3.  What does the sales tax for San Antonio pay for?

4.  Pretend you are an adult.  You would like to treat your partner to a meal.  How much will it cost?  What should you pay for tax? What should you pay for tip?  What is the total cost?

Wednesday, September 3, 2014

Scientific Notation Uses

We use scientific notation to deal with really big and really small numbers, especially when they are measurements.  The precision (how close the number is to the actual measurement) is based on how many numbers are represented in the notation.

So a number with many decimal places times a power of ten is more precise than a number with only a few decimal places times a power of ten.  2.9 times 10 to the 8th power is less precise than 2.98334 times 10 to the 8th power.

We use a trailing zero to indicate that there are no further numbers: 3.0 times 10 to the 3rd power is 3000, whereas 3.238 times 10 to the 3rd power is 3238...etc.