Sure, plant them out. Place them in the soil to where the roots are at least 2" below the surface. You may not get a fully mature divided bulb but there's a good chance that you will. Being store-bought, it's 99% certain that it's an early softneck type. Those can still be planted here with reasonable expectations.

Martin

thanxMartin,i was excited to get positive responce. should i seperate each clove that has sprouted? plant seperatly or all together in a bunch.
also have a visaila onion (soft ball size) that has 6-8 green sprouts coming out the top??? will it reproduce?

Separate the garlic cloves and plant them individually about 8" apart.

Your onion is a different story. If planted, best that you can hope for is some nice scallions. Used to do that early every spring for green onions if there were any sprouted in storage. But if they go beyond the scallion stage, they'll want to go to seed and won't make a bulb.

Martin