Convert all of your decimals to fractions, or all of your fractions to decimals, if the equation contains a mix of them both. If you want to convert fractions to decimals, simply divide the top number by the bottom number. When converting decimals to fractions, ignore any zeroes on the far right, such as the zero in 3.50. Make a fraction with all of the numbers in the decimal over a number corresponding to the last decimal place. Express the fraction in terms of tenths if the last number of the fraction is in the tenths place, or hundredths if the last number of the fraction is in the hundredths place, and so forth. For example, 3.50 converts to 35 / 10.
Perform all multiplication and division tasks. Write the product or quotient in place of the multiplication or division part of the equation.
For example, in the equation 5 x 10 + 5.3 / 0.5 - 3.6 - 5, first multiply 5 x 10, getting 50. Then divide 5.5 by 0.5, getting 11. After you replace "5 x 10" with "50" and "5.5 / 0.5" with "11," your equation should read: 50 + 11 - 3.6 - 5.
Perform all addition tasks. Replace the addition task with the acquired sum.
Following the same example, in the equation 50 + 11 - 3.6 - 5, you know that 50 + 11 = 61, so replace "50 + 11" with 61. The equation now reads: 61 - 3.6 - 5.
Perform all subtraction tasks. If the equation contains more than one subtraction task, move from left to right.
Following the same example, first perform the subtraction task: 61 - 3.6, which equals 57.4. Then subtract 5 from 57.4, getting the final number, 52.4.