I need to submit my project but the only thing I fall at is adding a loop so can someone recommend me a loop which I can add in my calculator
@studyprofutureamrl, it will help if you post an image of your blocks or a link to your project. Without either one, it is hard to know what you have done and where the problem might be. 
That’s just not enough information for anyone to be able to help you. Please review the “How to Ask Great Questions” link below.
·····················································································································
Need help? How to Ask Great Questions 
Debugging A Project API JSON Tutorial
Want to hire a Certified Thunkable Expert? Elevate your app with Tatiang on Fiverr