Using the place value chart, we can see that the decimal 0.4 is four tenths, so we can write 0.4 as the fraction [tex]\frac{4}{10}[/tex]. Notice however that the fraction is not in lowest terms. We will need to divide the numerator and the denominator by the greatest common factor of 4 and 10 which is 2. Therefore, 0.4 can be written as the fraction [tex]\frac{2}{5}[/tex], which is in lowest terms.
We can change a decimal to a percent by moving the decimal point 2 places to the right. In this problem, to change 0.40 to a percent, we move the decimal point 2 places to the right. When we have done this, we can add the percent sign so we have 40%. 0.40 can be read as 40 hundredths, or [tex]\frac{40}{100}[/tex] which we know is 40%.
