Hello I am new to this post so this question most likely has been answered somewhere else. Just in case I can't find it though can someone give me ideas for stretching the achilles in an effort to improve plie. Besides flexing and hanging off a step what other things can be suggested. I would like to include some different stretches for my students that are safe and age appropriate, ie children under 12 years.

Walk up really Big Hills
This is not a studio based way of stretching the Akilees but it works, well.

Here's the stretch I was prescribed by my physical therapists that has helped me a LOT.

Get a square board, and prop it up at an angle--maybe about 45 degrees. Put your right foot on the board, with your heel on the floor. Keeping your right knee straight, lean forward until you feel a stretch. Hold the stretch for 30 seconds, release and repeat. You really need to hold the stretch for 30 seconds, and repeat it 3 times. Most of us don't hold our stretches nearly long enough to do any good. Then, do the left leg.
The next stretch starts off the same, but this time, when you lean forward, bend your knee of the foot that is on the board. You should feel even more stretch a little lower, from your achilles and down along the bottom of your foot. Hold each time for 30 seconds.

My plie has gotten a lot better since I've been doing these stretches. The first time I held these stretches for 30 seconds, I got sore, and my therapist said to reduce it to 15 seconds and work my way up. So you might have to do that at first.

By the way, I actually saw a dance magazine selling a wedge shaped thing that you would use for this exact purpose. But really, you can just prop a board up at an angle for free.

Thanks everyone for your suggestions.

Good suggestions. I just wanted to be sure that we're clear that, technically, tendons don't stretch. The achilles is attached like the end of a hook to the base of the calf muscle, and so when we do these exercises, it's really the calf muscle that being worked and stretched out, not the tendon itself. And as a previous poster found out, you can over do it, so to build up gradually as with any exercise is prudent.

If I'm remembering my anatomy lessons/kinesiology lessons correctly from way back when, muscles stretch (when warm and *relaxed* -- which is one reason why tension is to be chassed away until got rid of), ligaments stretch a little and tendons virtually not at all.

absolutely right: tendons don't strech. You can work on the muscles, a little bit on the ligaments. Take care of the students under 12, take it easy!