I recently started to realize that Excel is a powerful tool that can solve many problems. What interesting mathematics problems are there can be solved using excel? I am looking for a set of challenges to try and solve using excel and to try and gain a better understanding of excel while having fun (problem solving).
There are many books (including free e-books) on the matter.
Here is a scattering of book examples (spreadsheets can do many amazing things and one of my instructors used it in numerical analysis and it was amazing to see, especially since I am more a Mathematica person).
Practical Numerical Analysis using Microsoft Excel, by A. Nandy
Applied Calculus with Microsoft Excel, Chester Piascik
Applied Mathematics with Microsoft Excel, Chester Piasci
Introductory Econometrics: Using Monte Carlo Simulation with Microsoft Excel, Humberto Barreto, Frank Howland
Data Analysis and Decision Making with Microsoft Excel: With Decision Tools and Statistic Tools Suite, S. Christian Albright, Wayne L. Winston, Christopher James Zappe
Statistics with Microsoft Excel (5th Edition), Beverly Dretzke
Finance and Financial Engineering with Microsoft Excel, Vikram Nanda
Excel by Example: A Microsoft Excel Cookbook for Electronics Engineers, Aubrey Kagan
Excel for Scientists and Engineers: Numerical Methods, E. Joseph Billo
Excel Scientific and Engineering Cookbook (Cookbooks (O'Reilly)), David M Bourg
Here are some mentions of Excel related to data science.
However, to do these kind of problems right, one probably will need more than Excel.
You could use Excel to analyze and visual your personal finances (or any recurring numbers of have). Make some conditional formatting where you spend more or less than average. Make some simple prediction for the future etc. Make a monthly predicted overall...