Calculations on 2 variables and storing in 3rd variable

I had a query .

Suppose I have valve 1 which is open at 2 o clock then valve 1 stores the time and flow meter1 stores the reading of water tank 100mcube and then when valve 1 closes at 2:30 then it stores the time and now the water level is 175mcube…

If I have to show on a widget that water needed to fill the tank was(175-100=75mcube) at 2:30, is it possible ? I want to do this working on the blynk platform itself and not on my microprocessor.

Means on the blynk platform I shd be able to subtract the 2 datastreams and display it on a widget. My microprocessor will just push the data to blynk, it won’t do any working…

I am currently doing this on ubidots where it allows me to calculate in a synthetic variable and then display this synthetic variable value in a widget on dashboard.

Plz let me know if it’s possible, and if yes then how?

No, that’s not possible.
It is fairly straightforward in code on your MCU though.