Chapter 4 - Number Representation and Calculation - 4.4 Looking Back at Early Numeration Systems - Exercise Set 4.4 - Page 241: 32

$CDLXIX$

RECALL: $D=500 \\C=100 \\L=50 \\X=10 \\V=5 \\I=1$ When a smaller number is written before a bigger number, the smaller number is subtracted to the bigger number. Note that: $469 = 400+60+9 \\469 = (500-100) + 50+10 +(10-1) \\469=CDLXIX$