Question

fill in the missing number. 80% of \boxed{} = 640

Explanation:

Step1: Convert percentage to decimal

80% can be written as $0.8$. Let the missing number be $x$. The equation becomes $0.8x = 640$.

Step2: Solve for x

To find $x$, divide both sides of the equation by $0.8$. So, $x=\frac{640}{0.8}$.
Calculating $\frac{640}{0.8}$, we get $x = 800$.

Answer:

800