Question

now its time to practice on your own
use a 10-squares model to solve.
4 is 40% of what number?
○ 10
○ 15
○ 40
○ 400

Explanation:

Step1: Define unknown number

Let the unknown number be $x$.

Step2: Set up percentage equation

40% of $x$ equals 4, so:
$$0.4x = 4$$

Step3: Solve for $x$

Divide both sides by 0.4:
$$x = \frac{4}{0.4} = 10$$
(For the 10-squares model: 10 squares represent 100%, so 1 square = 10%. 40% is 4 squares, which equals 4. Thus 1 square = 1, so 10 squares = 10.)

Answer:

10 (Option A)