To do Squat Jacks, start standing with your feet together. Reach your hands up overhead and then sink into a little squat. Make sure to sit your butt back. This position should look like Chair Pose.
Staying low in the squat, jump your feet out wide, about shoulder-width apart. As you jump out, also bring your hands down and in between your legs to reach for the ground. Do not stand up out of the squat as you jump your feet out wide. Try to touch your hands to the ground as you keep your butt down in the squat and chest up. Even try to squat lower as you jump your feet out wide.
Then jump your feet back together and bring your hands back overhead.
Stay low in the squat the entire time and move quickly. Try not to stand up as you jump your feet back in. However, beginners may need to stand up as they bring their feet together and only squat as they jump their feet out.