Right click/tap -> Halve qty of food entries

The no. 1 feature I want is a simple halve or divide-by-ratio for logged foods. This is why it's useful. 1) I cook a stir fry, measuring oil, meat, vegetables, log it as I go. 2) I eat half the stir fry and get full. 3) I put the other half in the fridge. Now when I go back to Cronometer, I have to manually adjust the quantities of each ingredient, doing the math, working with the serving sizes, etc. It would be so much easier just to select all and tap "halve qties". Thanks in advance, as this will save users time.