This is the 731st most frequent Japanese word.
弾
"弾" means "bullet," "shot," or "elasticity," depending on context.
Here, '弾' refers to bullets as ammunition.
その銃にはまだ弾が残っています。
There are still bullets left in that gun.
In this context, '弾き方' ('hiki-kata') uses '弾' to mean 'to play' an instrument like a piano.
彼はピアノの弾き方がとても上手です。
He is very skilled at playing the piano.
Here, '弾む' ('hazumu') derives from '弾' and means 'to bounce' or express buoyancy in emotions.