Adding and Subtracting Decimals Examples in Math
Start with the recap, study the fully worked examples, then use the practice problems to check your understanding of Adding and Subtracting Decimals.
This page combines explanation, solved examples, and follow-up practice so you can move from recognition to confident problem-solving in Math.
Concept Recap
Adding and subtracting numbers with decimal points by aligning the decimal points vertically so that digits with the same place value line up.
Think of money: \3.75 + \2.50. You line up the dollars with dollars, the dimes with dimes, and the pennies with pennies. The decimal point is the anchor that keeps everything in the right place.
Read the full concept explanation →How to Use These Examples
- Read the first worked example with the solution open so the structure is clear.
- Try the practice problems before revealing each solution.
- Use the related concepts and background knowledge badges if you feel stuck.
What to Focus On
Core idea: The decimal point must be aligned so that tenths add to tenths, hundredths add to hundredths—same-place-value digits must be combined.
Common stuck point: Adding numbers with different numbers of decimal places (e.g., 3.5 + 2.75)—pad with a zero: 3.50 + 2.75.
Sense of Study hint: Rewrite both numbers with the same number of decimal places by padding with zeros before lining them up.
Worked Examples
Example 1
easySolution
- 1 Line up the decimal points:
- 2 3.4
- 3 + 2.7
- 4 Tenths: \(4+7=11\), write 1, carry 1.
- 5 Ones: \(3+2+1=6\).
- 6 Result: 6.1.
Answer
Example 2
mediumPractice Problems
Try these problems on your own first, then open the solution to compare your method.
Example 1
easyExample 2
mediumRelated Concepts
Background Knowledge
These ideas may be useful before you work through the harder examples.