Create a nonlinear function (non-linear functions usually contain a variable term with an exponent) and provide two inputs for your classmates to evaluate

Answer 1

Write a function y(x) that is NOT of the form y = mx + b
where m and b are constants.

Here are some examples:

y = 1/x
y = 2*sqrtx
y = 3x^2 + 2

You should be able to think of others yourself.

Then pick two x values. Let someone else evaluate y for each x.

This does not seem like a very effective way to teach algebra.