One serves as a timekeeper, using a watch or clock. When the timekeeper says start, the other student squeezes a tennis ball as many times as possible, counting each squeeze. At the end of 15 seconds, the timekeeper says stop and records the number of squeezes. The child who squeezes the ball should note how tired her hand feels. Then students multiply the number of squeezes by 4 to determine the number of squeezes that would be made if they kept up the same pace for 60 seconds, or one minute.
Students can reverse roles so each has an opportunity to squeeze the tennis ball.
Instead, it is shaped more like an upside-down pear. Look at a real pear or a picture of a pear and make a drawing of a person with a pear-shaped heart. Don't forget to tilt the bottom a little toward the left side of the chest. Your heart is about as big as your fist. It is wider at the top and more pointed at the bottom.