Solve Decimal Addition: 2.5 + 3.1 Step-by-Step

Decimal Addition with Column Alignment

2.5+3.1= 2.5+\text{3}.1=

โค๏ธ Continue Your Math Journey!

We have hundreds of course questions with personalized recommendations + Account 100% premium

Step-by-step video solution

Watch the teacher solve the problem with clear explanations
00:00 Solve
00:03 We will use long addition for calculation
00:09 We will place the decimal point in the appropriate position
00:12 We will start by adding the smallest corresponding digits
00:16 We will place and continue to add and calculate
00:19 And this is the solution to the question

Step-by-step written solution

Follow each step carefully to understand the complete solution
1

Understand the problem

2.5+3.1= 2.5+\text{3}.1=

2

Step-by-step solution

To solve this problem, we'll follow these steps:

  • Step 1: Align the numbers 2.5 and 3.1 by their decimal points.
  • Step 2: Add the digits in each column starting from the rightmost digit (the tenths column in this case).

Now, let's work through each step:

Step 1: Align the numbers by decimal points:

002.5 \phantom{00}2.5
+3.1 +3.1

Step 2: Perform the addition:
- Add the tenths column: 5+1=6 5 + 1 = 6
- Add the units column: 2+3=5 2 + 3 = 5

Therefore, by aligning and adding the numbers correctly, the solution to the problem is 5.6 5.6 .

3

Final Answer

5.6

Key Points to Remember

Essential concepts to master this topic
  • Alignment: Line up decimal points vertically before adding digits
  • Technique: Add column by column: tenths 5+1=6, units 2+3=5
  • Check: Count decimal places: both numbers have one, answer has one โœ“

Common Mistakes

Avoid these frequent errors
  • Adding without aligning decimal points
    Don't just add 25 + 31 = 56 without considering decimal placement! This ignores the actual value of each digit and gives wrong results. Always align decimal points first, then add column by column.

Practice Quiz

Test your knowledge with interactive questions

Choose the correct writing form:

FAQ

Everything you need to know about this question

Why do I need to line up the decimal points?

+

Lining up decimal points ensures you're adding digits with the same place value. The tenths column must align with tenths, units with units, and so on!

What if one number has more decimal places than the other?

+

No problem! You can add invisible zeros to make them equal. For example, treat 2.5 as 2.50 when adding to 3.14.

How do I know where to put the decimal point in my answer?

+

The decimal point in your answer goes in the same column as the decimal points in the numbers you're adding. It stays aligned!

Can I add decimals from left to right like regular addition?

+

Yes! Once your decimal points are aligned, add each column from right to left just like whole number addition, carrying over when needed.

What if I get confused about place values?

+

Remember: the first digit after the decimal is tenths, the second is hundredths. In 2.5 2.5 , the 5 is in the tenths place.

๐ŸŒŸ Unlock Your Math Potential

Get unlimited access to all 18 Decimal Fractions - Advanced questions, detailed video solutions, and personalized progress tracking.

๐Ÿ“น

Unlimited Video Solutions

Step-by-step explanations for every problem

๐Ÿ“Š

Progress Analytics

Track your mastery across all topics

๐Ÿšซ

Ad-Free Learning

Focus on math without distractions

No credit card required โ€ข Cancel anytime

More Questions

Click on any question to see the complete solution with step-by-step explanations