From Knitting New Scarves:

Making this scarf is a great way to use up bits of yarn leftover from finished projects. It is also a perfect project for teaching children to knit. If you choose to work with a child on this scarf, I recommend letting the child knit the background sections while you knit the cross-through pieces and interlock them. Eight stitches by seventeen rows should work up in no time for a child, who will quickly move on to a new piece with a different color or yarn, avoiding potential boredom. Cast-on and bind-off instructions will stick with them, because they will have reason to practice those frequently on each new piece. If interest begins to wane before the scarf is long enough to wear, then look for some ribbon to attach to each end and transform it into a necklace.

Requires two US 8 double-pointed needles, and one spool of .8 mm clear elastic cord.