Copyright Goodheart-Willcox Co., Inc. May not be reproduced or posted to a publicly accessible website. Name __________________________________ Date _____________ Class _____________ 7 anekoho/Shutterstock.com UNIT 2 Addition of Whole Numbers Key Terms addition basic operations carrying sum Introduction Whole numbers are manipulated in arithmetic by four basic operations—addition, subtraction, multiplication, and division. The most widely used of these four opera- tions is addition. You will learn about addition in this unit. The other three basic operations will be studied in following units. Method Used to Add Whole Numbers Addition is the process of combining two or more individual numbers to form a single number that usually has a higher value than any of the previously indi- vidual numbers. Whole numbers are added by stacking the numbers to be added in a column with all the units on the right side lined up one on top of the other. units units units 4,956 27 354 21 192 2,032 191 11 111 256 1,542 9,461 + 10,431 + 5 + 17 It is important that all of the digits for each place value line up exactly above other digits of the same place value. Refer to the illustration of place values in Unit 1. Once each column has been calculated, a fi nal answer is reached. The fi nal answer in addition equations is called the sum. Select the icons to access Drill and Practice activities. Ch01.indd 7 5/3/2019 11:10:17 AM