Estimation, Graphs and Mathematical Models Lesson 1.2 Estimation, Graphs and Mathematical Models

Estimation – process of arriving at an approximate answer to a question Rounding is an estimation method Place values 2 9 5 , 7 3 4 , 1 3 4. 1 4 7 5 9 2

Rounding Whole numbers Look at digit to the right of the digit being rounded. 5 or greater round up Less than 5 round down This symbol ≈ means approximately equal to.

Round the U.S. population (311,591,917) To the nearest million To the nearest thousand.

Estimation by Rounding You purchased bread for $2.95, detergent for $2.17, a sandwich for $3.65, an apple for $0.47 and coffee for $5.79. The total bill was $18.67. Is this reasonable.

You earn $11 an hour at a part time job. What is your weekly salary (you work 20 hrs/ week) What is your annual salary.

Pie Charts (Circle Graphs) are divided into pieces called sectors.

Bar graphs are convenient for showing comparisons among data

Line Graph – illustrate trends over time.

Formula – statement of equality that uses letters to express a relationship between two or more variables. Finding Formulas to describe real-world phenomena is called mathematical modeling.

6 – 30 even 43 – 52 all on pg 23