Estimation
Today's Questions to Answer: ~What is estimation? ~When can we use it? ~What types of estimation are available?
What is estimation? Estimation: The process of finding an approximate answer to a math problem Here's a situation: You are looking to buy a new pair of shoes that cost $70. You find them on sale and are 40% off. About how much are the shoes?
Key words to hint estimation: Round About Estimate Approximately Rounding: When rounding, you will need to know place values 8, 9 8 5, 7 3 0, 2 6 1 . 2 3 5 7 6 5
Example 1) a) 7,328 (hundreds) b) 15, 683 (thousands) Round each number to the place value given: a) 7,328 (hundreds) b) 15, 683 (thousands) c) 32.4817 (tenths) d) 0.047812 (ten-thousandths)
Example 2) The owner of an apartment complex needs to buy six refrigerators for a new building. She chooses a model that costs $579.99 per refrigerator. Estimate the total cost of all six.
You're considering a new cell phone plan where you have to par $179 up front for the phone but the monthly charge of $39.99 includes unlimited minutes and texts. Estimate the cost of the phone for 1 year if there are no additional charges.
Estimation with Graphs: Bar Graph: Used to compare amounts or percents using either vertical or horizontal bars of various lengths which correspond to the amounts or percents Pie Chart (Circle Graph): Constructed by drawing a circle and dividing into parts according to the size of the percentage of each portion in relation to the whole Line Graph (Time Series Graph): Graph that represents how something changes over time
a) Estimate the number of votes for onions. Reading Graphs: Example 3) The bar graph below shows the votes of a recent lunch contest to decide which pizza topping is the best. a) Estimate the number of votes for onions. b) Estimate the difference in the number of votes for broccoli and sausage.
Example 4) Ms. Sweeney keeps track of some of the interesting excuses she hears for missing homework. Some are shown in the pie chart below. Approximate the percentage of students that blamed another person or animal for their missing homework.
Example 5) The graph below shows Luis's bike trip over time. Estimate the amount of kilometers Luis traveled from 11 to 2.
One final question... About how long did it take for this class to review this presentation?
Questions?