It is quite funny that quilting involves cutting a large piece of fabric into smaller pieces, only to sew them back together into a large piece of fabric again.
Alas, this is the plight of every quilter, and while it's the process we all must go through, having the right rulers in your arsenal of tools will help your piecing go together correctly.
We recommend that you start with four to six simple rulers for a couple of reasons. The suggestions are based on sub-cutting, strip cutting, squaring your block, creating a block, and learning to trim a block successfully.
Without these rulers, you will increase your chances of making blocks that do not measure correctly.