This is the 3450th most frequent Japanese word.
珠算
Abacus calculation.
In this sentence, "珠算" refers to the skill or practice of using the abacus for calculations.
彼は珠算の技能で賞を取った。
He won an award for his skill in abacus calculation.
Here, "珠算" is used to denote the general practice or method of abacus calculation historically.
珠算は昔の商人にとって重要でした。
Abacus calculation was important for merchants in the past.
In this context, "珠算" represents learning or teaching the technique of calculation using the abacus.