Calculus is one of the more intimidating ideas in mathematics, but at its root it’s just about change. Continuous change.
For example, a staircase has a changing slope, but because it is composed of right angles we can use algebra to figure things out. The same applies for a ramp–it’s at an angle, but it’s a consistent angle and length, so again algebra works.
But what happens if we’re examining a skateboard ramp like this:
Now the tools we learned in algebra no longer work because the slope is changing continuously. Enter calculus.