Coordination usually refers to whether a child can get the arms and legs to work together in a coordinated, effective way.
Work on touching the SAME SIDE hand or elbow to you knee, then switch sides!
NEXT, work on touching the OPPOSITE hand or elbow to you knee - alternating sides.
Start slow to get the correct movements then increase the speed to increase the difficulty.
VARIATIONS: Hand to thigh, Hand to foot
Jumping Jacks can be tricky, so try breaking it down with the below tips:
Try legs only, then arms only then both movements
A LONG pause between (ie feet together, arms down - PAUSE - feet apart and hands overhead together - PAUSE).
Do these in front of your child so you can set the pace and demonstrate at the same time.
Slowly speed up the movement as you can while maintaining the correct movements