Function notationComposing f(g(x))
Work the inside function first, then the outside one.
f(g(2)) means work g(2) first, then feed its answer into f. These free printable worksheets compose two functions and evaluate them, inside rule first.
If they get stuck

The answer key prints on a separate page.
Composition adds the one reliable mistake to function notation: working the outside first. f(g(2)) is read left to right and worked right to left — find g(2), then put that number into f. Choosing which rule is inside is what a test actually asks, and it is the whole of what this sheet drills.
The arithmetic is kept light on purpose so the order is what shows. Every rule is a straight line and every answer is a whole number, so a child is never fighting heavy computation while also tracking which function goes first. What is being practiced is the reading and the sequence, not the sums.
One question from a sheet like this one, worked a step at a time — with a sentence saying what just happened and why.
Composing functions, step by step