In this screen there will be a Record Drink button.Click on it.
After clicking on it this screen will show up.Click on the fraction of the glass you drank.
If you wanted to enter the volume of the glass you would click on the volume button and enter the volume of the glass and also the fraction filled from the previous step .
Save your glass and you're done.The glass in the main screen will have been filled up with some water.
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