Your homework is to duplicate today’s class at home making another pencil skirt in a woven fabric, take in skirt that was made in class 1.5 cm on each side, purchase a package of waistband elastic to install in the skirt, ask for help at Fabricland they all know me at the Barrie store so they will be able to guide you in the right direction. You understood how important the fabric width is in determining the amount of fabric needed for the project so I would recommend you take the pattern pieces with you and place them on the fabric to see if you have enough. This excercise will clarify even further how to purchase fabric. You will need an extra 10 cm for the waistband.
Have a great couple of weeks!