Before dinner, she had 56+8=<<56+8=64>>64 ounces of CM.
Before drinking 8 ounces of CM during lunch, she had 64+8=<<64+8=72>>72 ounces of CM.
Before buying 64 ounces of CM, she had 72-64=<<72-64=8>>8 ounces of CM.
And before breakfast, she had 8+8=<<8+8=16>>16 ounces of chocolate milk.
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