From 19 take away 1 leave with 20 how is this done?

Use roman numerals 19 = XIX take I away and you have XX = 20 if u have 19 sticks and u take away 1, u have 18 sticks TWENTY = 18 sticks to spell out the Word T=2 W=4 E=4 N=3 T=2 Y=3 2+4+4+3+2+3=18