頭あたまを使つかう

expression, godan verb (-u)

use one's head; think; use one's brain

Encourages or describes thinking carefully, solving a problem mentally, or applying intelligence rather than brute force.

• もっと頭あたまを使つかえば、その問もん題だいは簡かん単たんに解とけるよ。

  If you use your head a bit more, you can solve that problem easily.

• 力ちからだけじゃなくて、頭あたまを使つかうことも大たい切せつだ。

  It's important to use your head, not just brute strength.