Instruct students to write decimal addition and subtraction problems vertically, lining up the decimal and place values of the augend and addend or minuend and subtrahend.
Tell students to place a decimal on the sum or difference line that lines up with the decimal placement in the addition or subtraction problem before solving the problem. This ensures correct decimal placement in the answer.
Teach students to solve the problem from right to left, as they would a whole number addition or subtraction problem.
Instruct students to multiply numbers with decimals as they would a whole number multiplication problem.
Tell students to count the total amount of decimal places (digits behind the decimal) in the multiplicand and multiplier and to match the number of decimal places in the product to that number.
Teach students to count from right to left when placing the decimal in the product.
Tell students to look at the divisor and to move the decimal in the divisor to the right the necessary amount of times to make the divisor a whole number.
Instruct students to count the amount of places they moved the divisor decimal and to move the dividend decimal the same amount of places to the right.
Ask students to place a decimal on the quotient line that lines up with the decimal in the dividend. Tell students to solve the division problem, as they would a whole number division problem.