What is the least number which should be subtracted from 0.000326 to have perfect square ?

Options

A. `0.000004`
B. `0.000002`
C. 0.04
D. 0.02

Answer

To find the least number that should be subtracted from 0.000326 to make it a perfect square, we can follow these steps:

### Step 1: Understand the number
The given number is 0.000326. To simplify our calculations, we can express this number in a more manageable form by moving the decimal point to the right. This gives us:
\[ 0.000326 = \frac{326}{1000000} \]

### Step 2: Identify the nearest perfect square
Next, we need to find the nearest perfect square less than or equal to 326. The perfect squares close to 326 are:
- \(18^2 = 324\)
- \(19^2 = 361\)

Since 361 is greater than 326, we will consider 324 as the nearest perfect square.

### Step 3: Calculate the difference
Now, we need to find out how much we need to subtract from 326 to get to 324:
\[ 326 - 324 = 2 \]

### Step 4: Subtract from the original number
Since we need to subtract the same amount from 0.000326, we find:
\[ 0.000326 - 0.000002 = 0.000324 \]

### Step 5: Verify the result
Now, we check if \(0.000324\) is a perfect square:
\[ 0.000324 = \frac{324}{1000000} = \left(\frac{18}{1000}\right)^2 \]
This confirms that \(0.000324\) is indeed a perfect square.

### Conclusion
The least number that should be subtracted from 0.000326 to make it a perfect square is:
\[ \boxed{0.000002} \]