Laying down on back, knees pointing towards ceiling, feet on/near floor, then twist legs/hips to his left side, then return to original position, then to right side, original position again. Repeat a few times. (stretches and relaxes side abs
4. You sit in chair
, he sits on the floor with his back on your lower legs against a pillow. Hold his arms over his head while he sits with his back and stomach upright. Do for a few minutes.