Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall. Chapter 4 Decimals

Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall. 4.2 Order and Rounding

Martin-Gay, Developmental Mathematics, 2e 33 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall. Comparing Decimals One way to compare decimals is to compare their graphs on a number line. Numbers to the left are smaller and numbers to the right are larger. Comparing Two Decimals

Martin-Gay, Developmental Mathematics, 2e 44 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall. Comparing Two Decimals

Martin-Gay, Developmental Mathematics, 2e 55 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall. Example Insert, or = to form a true statement The tenths places are the same. The hundredths places are different. Since 4 > 3, > 0.632

Martin-Gay, Developmental Mathematics, 2e 66 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall. Example Write the decimals in order from smallest to largest , 3.517, 2.3, 2.03 By comparing the ones digit, the decimal is the largest number. To write the rest of the decimals in order, we compare digits to the right of the decimal point. We can insert zeros to help compare , 2.03, 2.3, 3.517

Martin-Gay, Developmental Mathematics, 2e 77 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall. Rounding Decimals

Martin-Gay, Developmental Mathematics, 2e 88 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall. Example Round to the nearest thousandth. Step 1: Locate the digit to the right of the given place value is to the right of the thousandth place value. Step 2: Since the digit to the right is less than 5, we delete it and all digits to its right. Thus rounded to the nearest thousandth is 0.594

Martin-Gay, Developmental Mathematics, 2e 99 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall. Example Round $0.067 to the nearest cent. Step 1: Locate the digit to the right of the given place value. $ is to the right of the hundredths place value Step 2: Since the digit to the right is more than 5, we round up. Thus $0.067 rounds to $0.07.

Martin-Gay, Developmental Mathematics, 2e 10 Copyright © 2011 Pearson Education, Inc. Publishing as Prentice Hall. Example An aquarium cats $ Round the price to the nearest dollar. The nearest dollar means the ones place. Locate the digit to the right of the ones place. $ is to the right of the ones place value Thus $ rounds to $