I'm not sure my math is correct but I did 6 2.5" strips WOF for the required number of HSQ using the easy angle ruler for step 1. I haven't finished yet so I may be off.
Zozee, breath and take a moment. So sorry about your mistake, I've had similar problems in the past. If fabric is no issue, I would start over so you will not have to relive the issue each week to recalculate the steps.
I do think this is easier so far then Celtic Solstis last year. Have most of my cutting done and about 1/3 of the sewing together. Have to travel this week so that will be all that gets done until Friday. I will have to sew a few more units together.