How to display parent component function value in child component of angular

I have a function in the parent component and i want to display the value in the child component. I tried an @Input decorator but i couldn’t. my function is

onTest(s) {

This console.log display one of the skill name from the lists. So i want it to display on the child component.
Can someone help me? Thanks

Can you post your components ? wanna know where to correct you exactly.