Financial literacy is the ability to understand how money works in the world: how someone manages to earn or make it, how that person manages it, how he/she invests it, and how that person donates it to help others.
I believe that my past Algebra 2 students understand the material. I don't think that they could go out and apply those concepts (for example in a job environment.)
Looking at exponential functions, for example, students can look at the depreciation of a new or their old car in terms of re-sale value. Students can enter the data and draw a scatter plot on a sheet of graph paper.
If students didn't have a car they could search for one. For example I searched my wife's car a 2015 Chevy Cruze.
The MSRP is $16,170
After the first year it depreciates: $7,904
After the second year: $1,200
After the third year: $1,000
After the fourth year: $875
After the fifth year: $675
Students could then plot this and look for the exponential line of best fit through that data on Desmos. You could then prompt follow up questions, what will the value be 8 years from now? Is $8,456 a good price now for a 2015 Chevy Cruze?
For slope and finding slope of a line, give them real-world data to extrapolate. This data below came from the Nebraska Department of Roads.
What is the slope of each year from January to May? What is the slope of each year from May to December? What causes this?
What do you expect June to look like? Can we determine what the price will be December?
Having students know the concepts is one thing. Having them use the concepts beyond the classroom is what we are looking for as math teacher.