You said that he's studying interview techniques -- he's studying math for cs, basic algorithms, and algorithmic design. He mentioned that whiteboarding has scared him, he did not say that he was studying only to get better at whiteboarding.
My issue was more with the answers given here, not the question asked. When I wrote this comment, the top comment and all of the others recommended studying interview questions, not algorithms and math FOR answering interview questions. That's what bothers me.