Fill in the blank: 0.00187 × ……… = 18.7

Concept: Multiplying a decimal by a power of 10 (10, 100, 1000, …) shifts the decimal point to the right by exactly as many places as there are zeros in that power of 10 — equivalently, the missing factor equals (target value) ÷ (given decimal).

Application:

1. Set up the equation: 0.00187 × y = 18.7, so y = 18.7 ÷ 0.00187.

2. Clear the decimals by multiplying numerator and denominator by 100000: y = (18.7 × 100000) ÷ (0.00187 × 100000) = 1,870,000 ÷ 187.

3. Divide: 187 × 10,000 = 1,870,000, so y = 10,000.

Cross-check: Multiplying 0.00187 by 10,000 shifts its decimal point 4 places to the right (as many places as the zeros in 10,000): 0.00187 → 0.0187 → 0.187 → 1.87 → 18.7, which matches the target value exactly.