Solving the Equation for the Missing Value

The problem asks us to find the value represented by the question mark (?) in the given equation:

$ (0.008 \div ?) + (0.006 \div 0.03) + (0.008 \div 0.04) = 0.5 $

We need to solve this equation using basic arithmetic operations.

Decimal Division Calculation Steps

1. Simplify the known division parts:

   • Calculate $(0.006 \div 0.03)$: $ \frac{0.006}{0.03} = \frac{6}{30} = \frac{1}{5} = 0.2 $
   • Calculate $(0.008 \div 0.04)$: $ \frac{0.008}{0.04} = \frac{8}{40} = \frac{1}{5} = 0.2 $

2. Substitute these values back into the original equation:

   $ (0.008 \div ?) + 0.2 + 0.2 = 0.5 $

   Simplify further:

   $ (0.008 \div ?) + 0.4 = 0.5 $

3. Isolate the term with the question mark:

   Subtract 0.4 from both sides:

   $ (0.008 \div ?) = 0.5 - 0.4 $

   $ (0.008 \div ?) = 0.1 $

4. Solve for the question mark (?):

   Let the question mark be represented by $x$.

   $ \frac{0.008}{x} = 0.1 $

   Rearrange the equation to solve for $x$:

   $ x = \frac{0.008}{0.1} $

   Perform the division:

   $ x = 0.08 $

Final Answer Verification

Substitute the calculated value (0.08) back into the original equation to check:

$ (0.008 \div 0.08) + (0.006 \div 0.03) + (0.008 \div 0.04) $

$ 0.1 + 0.2 + 0.2 = 0.5 $

The result matches the right side of the original equation (0.5), confirming our value for the question mark is correct.