Decimal Calculator
Add, subtract, multiply, and divide decimals with step-by-step solutions
How to Perform Decimal Operations
Working with decimals requires careful attention to decimal point placement. Each operation has specific rules to follow.
Addition and Subtraction
- Line up the decimal points vertically
- Add zeros as placeholders if needed
- Add or subtract as with whole numbers
- Bring down the decimal point to the answer
Multiplication
- Count total decimal places in both numbers
- Multiply as if they were whole numbers
- Count that many places from the right in your answer
- Place the decimal point there
Division
- Move the decimal in the divisor to make it a whole number
- Move the decimal in the dividend the same number of places
- Divide as usual
- Place decimal point in answer directly above
Common Decimal Operations
Addition
12.5 + 3.75 = 16.25
Subtraction
12.5 - 3.75 = 8.75
Multiplication
12.5 × 3.75 = 46.875
Division
12.5 ÷ 2.5 = 5
Frequently Asked Questions
How do you add decimals?
Line up the decimal points, add zeros as placeholders if needed, then add as normal. The decimal point in the answer goes directly below the others.
How do you multiply decimals?
Count the total decimal places in both numbers, multiply as whole numbers, then place the decimal point that many places from the right in your answer.
Why do you line up decimal points for addition but not multiplication?
In addition/subtraction, you're combining like place values. In multiplication, you're scaling, so decimal placement is determined by counting total decimal places instead.
How do you divide by a decimal?
Move the decimal point in the divisor to make it a whole number, then move the decimal in the dividend the same number of places. Then divide normally.
What if the numbers have different numbers of decimal places?
For addition/subtraction, add zeros to make them equal. For multiplication, count each number's decimal places separately. For division, the process handles this automatically.
Can decimal operations result in whole numbers?
Yes! For example, 2.5 + 2.5 = 5, and 3.6 ÷ 1.2 = 3. If the result is a whole number, the decimal point may not appear or will be followed by zeros.