Add decimals
- Line up decimal points.
- Use zeros as placeholders.
- Add each column.
Answer: 1.8 + 2.35 = 4.15
🔢 Number
Decimal addition
Learn decimal addition with a GCSE-style explanation, help guide, worked example, practice question and flashcards.
Global XP
Level 10 / 100 XP
1. Explanation
Key idea
- Decimal addition is part of decimals and appears often in KS3–GCSE maths.
- Line up decimal points for decimal addition.
- Use the worked model, help guide, interactive question and flashcards to practise decimal addition until the steps feel automatic.
Real-life examples
- Shopping, sport, travel, science, design and everyday decisions all use this skill.
2. Visual
Decimal addition learning map
Understand the key idea → follow the help guide → practise a question → check your method → build speed with flashcards.
3. Help guide
How to tackle Decimal addition
- Learn the rule: Line up decimal points for decimal addition.
- Worked model: Line up decimal points. Use zeros as placeholders. Add each column.
- Try the interactive question without looking at the answer first.
- Use the flashcards to test the rule, the method and a common check.
4. Worked examples
Step-by-step working
5. Interactive questions
Try it yourself
Calculate 3.45 + 2.7.
6. Flashcards
Master quick recall
Flip each card, then choose whether you know it or need more practice.
0 mastered
FrontRule for Decimal addition
BackLine up decimal points for decimal addition.
FrontExample answer: Calculate 3.45 + 2.7.
Back3.45 + 2.70 = 6.15.
FrontCommon check for Decimal addition
BackCheck units/notation, compare with an estimate, and make sure the answer matches the question.
7. Finish
Complete this topic
When you have read the examples, tried the question and reviewed flashcards, claim your topic completion XP.