What is the weight of one serving of grains?

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What is the weight of one serving of grains?

Grains

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One serving equals 1 slice of bread; 1/2 cup of cooked rice, pasta, or cereal; or 1 ounce of cold cereal. All of these serving sizes are known as "ounce equivalents" in Choose My Plate-speak.

As a general rule of thumb, 

1 serving size/ounce equivalent of bread = plastic CD case

2 servings/ounce equivalents of cooked brown rice = a tennis ball