Change the percent to a decimal. 0.4% =

0.4% = 0.4 / 100

When dividing by 100, since 100 has 2 zeros, we shift the decimal point in 0.4 to places to the left.

0.4 / 100 =        0.004

Hope this explains it.

It's like discovering the answer to a puzzle. the purpose in solving an equation is to find the value or values of the variable that makes it a true statement. any value of the variable that makes the equation true is called a solution to the equation.