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This document provides a detailed explanation of how to determine the validity of UPC-A codes using checksum validation, as well as how to find missing digits in such codes. We explore several examples, including a valid UPC-A code (0.11110.86852-7) and missing digit scenarios (0.21130.27566-?, 0.70?30.50606.0, 0.787?7.50758.6). Each case outlines the calculation steps for odd and even digit sums, the overall checksum calculation, and the method for identifying missing digits. Understanding these principles is essential for accurate UPC code management.
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Consider the following UPC-A code. Is it a valid UPC? 0 11110 86852-7
Consider the following UPC-A code. Is it a valid UPC? 0 11110 86852-7 The answer is Yes
How can we get ? • odd-digit sum: 0+1+1+8+8+2=20 • even-digit sum: 1+1+0+6+5=13 • odd*3+even = 20*3+13=73 • mod 10: 73 mod 10 = 3 • subtract from 10=10-3=7
Consider the following UPC-A code. What is the missing digit (shown as a question mark)? 0 21130 27566-?
Consider the following UPC-A code. What is the missing digit (shown as a question mark)? 0 21130 27566-? • The answer is 3
How can we get ? • odd-digit sum: 0+1+3+2+5+6=17 • even-digit sum: 2+1+0+7+6=16 • odd*3+even = 17*3+16=67 • mod 10: 67 mod 10 = 7 • subtract from10=10-7=3
Consider the following UPC-A code. What is the missing digit (shown as a question mark)?0 70?30 50606 0
Consider the following UPC-A code. What is the missing digit (shown as a question mark)?0 70?30 50606 0 • The answer is 3
How can we get ? • odd-digit sum: 0+0+3+5+6+6=20 • even-digit sum: 7+x+0+0+0=7+x • odd*3+even = 20*3+7+x=67+x • mod 10: (67+x)mod 10 • checking number is 0, so (67+x)mod10=0 =>x=3
Consider the following UPC-A code. What is the missing digit (shown as a question mark)?0 787?7 50758 6
Consider the following UPC-A code. What is the missing digit (shown as a question mark)?0 787?7 50758 6 • The answer is 8
How can we get ? • odd-digit sum: 0+8+x+5+7+8=28+x • even-digit sum: 7+7+7+0+5=26 • odd*3+even = (28+x)*3+26=110+3x • subtract from 10: 10-(110+3x)mod10=6 =>(110+3x)mod10=4 =>x=8