I recommend crocheting into the 'bump' or back of the chain in many of my patterns as the result is firmer and looks neater than the more usual way of crocheting into the 'V' or front of the chain.
1. This is the front of a chain of 11 stitches. To crochet into the bump, turn the chain towards you.
2. Now you can see the 'bumps' of the chain.
3. Crochet into the second 'bump' from the hook.
4. This shows 5 single crochet stitches worked into the chain, with 5 'bumps' to go.