These days, you tend to sketch math functions on the computer and there are plenty of people willing to take your money for the software. But if you fire up your browser, head over to EngineeringPaper.xyz and you might save a little cash.

Although it looks a lot like a Jupyter notebook, the math cells in EngineeringPaper keeps track of units for you and allows you to query results easily. Want to read more? Luckily, there is an EngineeringPaper worksheet that explains how to use it. If you prefer your explanations in video form, check out their channel, including the video that appears below.

https://engineeringpaper.xyz/

https://engineeringpaper.xyz/CUsUSuwHkHzNyButyCHEng

Sliders in GeoGebra
https://www.geogebra.org/m/KZDm6QEs

This screencast shows how to enter data into the Geogebra spreadsheet view, make a scatter plot, find a curve of best fit, and then import the model back into the graphics view for further analysis.