Usage patterns
〈人〉がマジックを披露するfor someone to perform a magic trick
He performed a magic trick at the party.
〈物〉にマジックで書くto write on something with a permanent marker
I wrote my name on the box with a permanent marker.
マジックが〈数〉になるfor the magic number to become (a certain number)
The magic number to clinch the championship became one.