We need to find the missing number in the equation $25 \div \Box = 0.25$.

1. Problem Description

We need to find the missing number in the equation $25 \div \Box = 0.25$.

2. Solution Steps

Let the missing number be $x$. The equation can be rewritten as:

$25 \div x = 0.25$

To solve for $x$, we can multiply both sides of the equation by $x$:

$25 = 0.25x$

Now, we can divide both sides by $0.25$ to isolate $x$:

$x = \frac{25}{0.25}$

To simplify the division, we can multiply both the numerator and denominator by 100:

$x = \frac{25 \times 100}{0.25 \times 100} = \frac{2500}{25}$

Now, divide 2500 by 25:

$x = 100$

3. Final Answer

100