We call our problem solving process, functional thinking. When we apply functional thinking to problem solving in the digital age, we find that a few fundamental models give us the tools to creatively solve quantitative problems. Think of functions as LEGOs, add columns using new rules, use outputs as new inputs, combine simple functions in new and creative ways.

**1**

**Visualize **the problem and set up **parameter** table with starting value **x _{0} ** and incremental Δ

**x**values (or in this case

**t**and Δ

_{0}**t**) of their inputs (independent variables), as well as the values of any “constants” that could be changed.

**4**

**Test and iterate** your model to improve it and solve the problem. Add graphs, conditional formatting, or other data representations to design the output to communicate the results.