Chrome extension for quick notes and calculations in the new tab
Your new tab page will be divided into two blocks: on the left, you have text/code editor for your quick notes or code snippets, on the right side you have "smart" calculator notepad, where you can perform basic math operations.
If you are not ready to use Chrome extension, feel free to try out web app version. It works the same way, the only difference is that it does not sync data with your Google account, but instead saves it localy in your browser's LocalStorage.