Calculate 5000 × 0.001.

• A. 5
• B. 0.5
• C. 50
• D. 500

Answer: (A)

Multiplying by a tiny decimal scales the number down by that factor, which means moving the decimal point to the left by the number of decimal places in the multiplier. Since 0.001 has three decimal places, you move the decimal three places to the left: 5000 becomes 5.000, i.e., 5.

Another way to see it: 0.001 is 1/1000, so 5000 × 0.001 = 5000/1000 = 5.

The other options come from moving the decimal left by different amounts (for example, 0.01 would give 50, 0.1 would give 500), or would require a different factor (0.0001 would give 0.5). So the correct result is 5.