I agree with those who said to not make it too detailed. The sewing on of buttons and the pencil cases sound good. Yo-yos in different sizes would be fun, especially if a few are put together to make a lapel pin or a large one for a pincushion. A square of fabric could be hemmed for a hankerchief, or a large square for a head scarf or neck scarf. An oblong of a heavier fabric like a heavy knit would make a neat dresser scarf. Something finished in a short time is far better than making a quilt block with no end in sight.

In our school district, the 4th grade class each year makes 'quilts' for a school demo project. I've been called on for the 2 niece's classes so far. They bring their purchased fabrics and hand sewing supplies (pins; needles; thread; snips). I cut all the fabrics. They have a choice now of doing a quilt or a pillow but use the same layout for either. Large 4 patch pieces. I sew seam lines on the squares and show them how to thread needles; knot thread; sew the seams. I usually end up reinforcing their work (unbeknownst to them) and then they stuff/sandwich as appropriate to their project. Show them how to close their seam once project is turned right side out. Let the teacher incorporate any 'math' skills they want.

I have done simple paper pieced squares for a first, hand-sewn project. Instead of paper, however, I used a muslin base. That provided stability in case the stitches weren't great (eg, size-wise). I've used a simple house pattern that I drew up. The lines help keep the sewing straight. I used the pillowcase method of turning the quilts and had them sew buttons and charms on to "quilt" it. I am now working with a 3rd grader and I suggested she make a 9-patch. I've taught her to mark and cut out the squares then mark the stitching lines. She pins and sews. When it's done, it'll become a pillow.

We used Genny Beyer's Puzzle Balls book to teach kids to hand sew- seems like she recommends that project for scouts... Anyway, fun projects, the kids love making the balls and the math lessons are part of the project including angles. I've had kids as young as 6 make puzzle balls. The only equipment is sewing needles and threads. Templates, scissors ( kids can cut out their own pieces with scissors { No Rotary Cutters Allowed!!! Too dangerous for children!!!!}