How to Crochet - Making a Base Chain with Single Crochet (abbreviated as base ch/sc)
Base ch/sc (Note: This method creates a base ch and a row of sc at the same time: easy, sturdy and elastic, especially useful for necklines and waistlines.) Start with a slip knot, ch 2, insert hook in 2nd ch from hook, draw up a loop, yo, draw through 1 loop, yo, and draw through 2 loops - 1 single crochet with its own chain at bottom. Work next stitch under loops of that chain. Insert hook under 2 loops at bottom of the previous stitch, draw up a loop, yo and draw through 1 loop, yo and draw through 2 loops. Repeat for length of foundation.