Once I get past my 10 fingers and toes, I'm lost at math. I hated any kind of math in school and college. I graphed a dresden quilt for my brother's Christmas. Thot I double checked etc.
Low and behold, I'm a yard short of my main fabric for the borders. I didn't want to change my original design so I went to several stores until I found a match. It got kind of frantic after the first few stores, but luckily I did find the material.
Needless to say, I bought an extra yard in case I messed up with the math again!