After completing this chapter, students will be able to: Explain the place values of whole numbers and decimals; round decimals; convert decimal fractions to decimals, proper fractions to decimals, mixed numbers to decimals, and pure and mixed decimals to decimal fractions; add, subtract, multiply, and divide decimals; complete decimal applications in foreign currency; multiply and divide decimals by shortcut methods. | Chapter Three Decimals Copyright © 2014 by The McGraw-Hill Companies, Inc. All rights reserved. McGraw-Hill/Irwin LU 3-1: Rounding Decimals; Fraction & Decimal Conversions Explain the place values of whole numbers and decimals; round decimals. Convert decimal fractions to decimals, proper fractions to decimals, mixed numbers to decimals, and pure and mixed decimals to decimal fractions. Learning unit objectives LU 3-2: Adding, Subtracting, Multiplying, and Dividing Decimals Add, subtract, multiply, and divide decimals. Complete decimal applications in foreign currency. Multiply and divide decimals by shortcut methods. Table - Bag of M&M’s Decimal Percent Color Fraction (hundredth) (hundredth) Yellow 18 .33 55 Red 10 .18 55 Blue 9 .16 55 Orange 7 .13 55 Brown 6 .11 55 Green 5 .09 55 Total 55 55 = 1 Decimal place-value chart 4 Rounding Decimals .337272 .33 .3272727 Step 1. Identify the place value of the digit you want to round. | Chapter Three Decimals Copyright © 2014 by The McGraw-Hill Companies, Inc. All rights reserved. McGraw-Hill/Irwin LU 3-1: Rounding Decimals; Fraction & Decimal Conversions Explain the place values of whole numbers and decimals; round decimals. Convert decimal fractions to decimals, proper fractions to decimals, mixed numbers to decimals, and pure and mixed decimals to decimal fractions. Learning unit objectives LU 3-2: Adding, Subtracting, Multiplying, and Dividing Decimals Add, subtract, multiply, and divide decimals. Complete decimal applications in foreign currency. Multiply and divide decimals by shortcut methods. Table - Bag of M&M’s Decimal Percent Color Fraction (hundredth) (hundredth) Yellow 18 .33 55 Red 10 .18 55 Blue 9 .16 55 Orange 7 .13 55 Brown 6 .11 55 Green 5 .09 55 Total 55 55 = 1 Decimal place-value chart 4 Rounding Decimals .337272 .33 .3272727 Step 1. Identify the place value of the digit you want to round. Step 2. Identify the digit to the right. If 5 or more, increase the identified digit by 1. If less than 5, do not change. Step 3. Drop all digits to the right of the identified digit. 3 Steps 5 Rounding Decimals Round to nearest dollar: $ Round to nearest cent: $1, Round to nearest hundredth: $ Round to nearest thousandth: $1, $1, $ $1, $166 6 Converting Decimal Fractions to Decimals 2 Steps 1. Count the number of zeros in the denominator. 2. Place the numerator of the decimal fraction to the right of the decimal point the same number of places as you have zeros in the denominator. Do not go over the total number of denominator zeros. Fraction Decimal # of places 3 10 3 100 3 1,000 3 10,000 .3 1 .03 2 .003 3 .0003 4 7 Converting Proper Fractions to Decimals 3 4 4 2 8 20 20 0 .75 Decimal 8 Converting Mixed Numbers to Decimals + .4 = 2 5 5 2 0 0 8 .4 Step 1 Step 2 8 9 24 1 24 24 100 2 .24 Step 1. Place the digits to the right