This is the 5828th most frequent Japanese word.
ひとつひとつ
"ひとつひとつ" means "one by one" or "each individually."
In this sentence, 'ひとつひとつ' is used to describe the deliberate and careful approach taken by the subject to handle tasks individually.
彼は仕事をひとつひとつ丁寧に片付けた。
He carefully completed each task one by one.
Here, 'ひとつひとつ' emphasizes the individual importance of each component contributing to the whole.
ひとつひとつの部品がこの製品を完成させる。
Each and every part contributes to completing this product.
In this case, 'ひとつひとつ' expresses the process of addressing questions individually and with care.