Copyright Goodheart-Willcox Co., Inc. May not be reproduced or posted to a publicly accessible website. 25 Objectives Information in this chapter will enable you to: ▪ Recognize each of the parts of a fraction and understand what they mean. ▪ Identify proper fractions, improper fractions, and mixed numbers. ▪ Compare, reduce, and raise fractions. ▪ Find the lowest common denominator (LCD) among fractions. ▪ List the factors of numbers and determine the greatest common factor. ▪ Understand prime numbers and recognize some of the most common prime ▪ Reduce fractions to their lowest terms. ▪ Add, subtract, multiply, and divide fractions. ▪ Convert a mixed number into an improper fraction. Technical Terms common denominator denominator factor fraction greatest common factor improper fraction lowest common denominator (LCD) lowest terms mixed number numerator prime number proper fraction reducing 2.1 Introduction to Fractions A fraction is defi ned as a portion of a whole. A fraction, therefore, is part of a whole fi number. HVACR technicians commonly in as and sizing inch, inch, 3/4 An understanding of fractions, their and basic as and is in the If the number 1 is broken into four equal portions, each portion would be 1/4 of the CHAPTER 2 Fractions Chap ter 2 Fractions 25 Ch 02.indd 25 10/31/2016 11: 45:46 AM Copyright Goodheart-Willcox Co., Inc. May not be reproduced or posted to a publicly accessible website. Chapter 3 Decimals 53 C h ter ls Name ___________________________________ Date _____________ Class ______________ Practical Exercise 3-4 A service technician has been given a listt of air-conditioning and refrigerant equipment that shows the amount of refriigerant that each unit holds in pounds only. However, the scale being used to weigh th refrigerant reads in pounds and ounces. 1. Convert each listing of pounds to pouunds and ounces, so the correct amount of refrigerant can be charged into each u Round down each answer to the closest ounce so the systems are not overcha There are 16 ounces in a pound. Total Refrigerant Charge Unit Refrigerant Pounds Pounds and Ounces RTU 1 R-2 2 7.12 RTU 2 R-1 34a 14.9 RTU 3 R-4 10A 9.5 AC 1 R-41 0A 3.16 AC 2 R-134a 4.25 AC 3 R-22 3.92 WI 1 R-12 19.35 WI 2 R-40 4A 22.1 WI 3 R-134a 44.22 IM 1 R-13 4a 0.94 IM 2 R-410A 1.02 IM 3 R-29 0 0.75 Goodheart-W illcox Publisher 2. How many pounds and ounces of ea of the different refrigerants would be needed to completely charge all of the systems at this facility? After calculating the totals, round up each answer to th closest pound. Total Refrigerant Charge Type Pounds and Ounces Rounded Up Pounds R-12 R-22 R-134a R-290 R-404A R-410A Goodheart-W illcox Publisher Ch03.indd 53 11/1 /2016 8:30:48 AM Objectives clearly identify the knowledge and skills to be obtained when the chapter is completed. Review Questions allow you to demonstrate knowledge, identification, and comprehension of chapter material. Introduction provides an overview and preview of the chapter content. Technical Terms list the key terms to be learned in the chapter. Review this list after completing the chapter to be sure you know the definition of each term. Copyright Goodheart-Willcox Co., Inc. May not be reproduced or posted to a publicly accessible website.. 190 Math for HVACRRC r Main Plenum − West View Main Plenum − East View Main Plenum − Bottom View Main Plenum − Top View 5 ′″-0 18 ′-0″ 4 -8 ″ 5′-0″ 10′-0″ 1′-0″ 18″ × 24″ duct 5 ′″-0 18′-0″ 4 -8 ″ 5′-0″ 10′-0″ 1′-0″ 18″ duct 7′ -6″ Break li ne Seam 22′-0 ″ 18″″ × 72″ louvered opening 7′ -6″ Break li n ne 22′-0″ 24″″ × 72″″ duct Goodheart-Willcox Publisher Ch08. indd 190 11/8/2016 10:15:0 2 AM Illustrations have been designed to clearly and simply communicate the specific topic. vi Features of the Textbook Features are student-focused learning tools designed to help you get the most out of your studies. This visual guide highlights the features designed for the textbook.