Find the 5 - digit number which is a perfect square.

Answer

To find the largest 5-digit number which is a perfect square, we can follow these steps:

### Step 1: Identify the largest 5-digit number
The largest 5-digit number is 99999.

### Step 2: Calculate the square root of the largest 5-digit number
To find the largest perfect square that is a 5-digit number, we need to calculate the square root of 99999.

### Step 3: Estimate the square root
We can estimate the square root of 99999. The square root of 100000 is 316.227, so we can start by checking the integer part, which is 316.

### Step 4: Calculate the perfect square of 316
Now we will calculate \( 316^2 \):
\[ 316 \times 316 = 99856 \]

### Step 5: Verify if 99856 is a 5-digit number
Since 99856 is indeed a 5-digit number, we can conclude that it is a perfect square.

### Conclusion
The largest 5-digit number which is a perfect square is **99856**.

---